Complete Mathematics Formulas Guide for Class 6 to 10
Mathematics is built on fundamental formulas that serve as building blocks for advanced concepts. This comprehensive guide presents essential formulas from Class 6 through Class 10, organized systematically to help students master mathematical concepts with clarity and confidence.
Class 6 Mathematics Formulas
1. Number System
| Concept | Formula | Explanation |
|---|---|---|
| Whole Numbers | 0, 1, 2, 3, 4, … | Numbers starting from zero with no fractions |
| Natural Numbers | 1, 2, 3, 4, 5, … | Counting numbers starting from 1 |
| Integers | …, -3, -2, -1, 0, 1, 2, 3, … | Whole numbers including negative numbers |
| Even Numbers | 2n (where n is any integer) | Numbers divisible by 2 |
| Odd Numbers | 2n + 1 (where n is any integer) | Numbers not divisible by 2 |
2. Basic Arithmetic Operations
| Operation | Formula | Example |
|---|---|---|
| Addition | a + b = sum | 5 + 3 = 8 |
| Subtraction | a – b = difference | 10 – 4 = 6 |
| Multiplication | a × b = product | 6 × 7 = 42 |
| Division | a ÷ b = quotient | 20 ÷ 4 = 5 |
3. Fractions
| Concept | Formula | Explanation |
|---|---|---|
| Proper Fraction | Numerator < Denominator | Example: 3/5, 2/7 |
| Improper Fraction | Numerator ≥ Denominator | Example: 7/3, 5/5 |
| Mixed Fraction | Whole number + Proper fraction | Example: 2¹/₃ |
| Addition of Fractions | a/b + c/d = (ad + bc)/bd | Cross multiply and add |
| Subtraction of Fractions | a/b – c/d = (ad – bc)/bd | Cross multiply and subtract |
| Multiplication of Fractions | a/b × c/d = (a × c)/(b × d) | Multiply numerators and denominators |
| Division of Fractions | a/b ÷ c/d = a/b × d/c | Multiply by reciprocal |
4. Decimals
| Concept | Formula/Rule | Example |
|---|---|---|
| Decimal to Fraction | Place value method | 0.5 = 5/10 = 1/2 |
| Addition of Decimals | Align decimal points | 2.5 + 3.75 = 6.25 |
| Multiplication of Decimals | Multiply, count decimal places | 2.5 × 0.4 = 1.00 |
5. Ratio and Proportion
| Concept | Formula | Explanation |
|---|---|---|
| Ratio | a : b or a/b | Comparison of two quantities |
| Proportion | a : b = c : d or a/b = c/d | Equality of two ratios |
| Mean Proportional | b² = ac (if a : b = b : c) | b is mean proportional between a and c |
6. Percentage
| Concept | Formula | Explanation |
|---|---|---|
| Percentage | (Value/Total) × 100% | Parts per hundred |
| Converting Fraction to % | (Fraction) × 100% | Multiply fraction by 100 |
| Converting % to Fraction | %/100 | Divide percentage by 100 |
| Percentage Increase | [(New – Old)/Old] × 100% | Change relative to original |
| Percentage Decrease | [(Old – New)/Old] × 100% | Decrease relative to original |
7. Geometry – Basic Shapes
| Shape | Perimeter | Area |
|---|---|---|
| Square | 4 × side = 4s | side² = s² |
| Rectangle | 2(length + breadth) = 2(l + b) | length × breadth = l × b |
| Triangle | a + b + c (sum of all sides) | ½ × base × height = ½ × b × h |
| Circle | 2πr (Circumference) | πr² |
8. Mensuration (Basic)
| Concept | Formula | Units |
|---|---|---|
| Perimeter | Sum of all sides | cm, m, km |
| Area | Space inside a shape | cm², m², km² |
| Volume | Space inside 3D object | cm³, m³, l |
Class 7 Mathematics Formulas
1. Integers
| Operation | Formula/Rule | Example |
|---|---|---|
| Addition (same sign) | Add and keep sign | (-5) + (-3) = -8 |
| Addition (different sign) | Subtract and use larger sign | (-5) + 3 = -2 |
| Multiplication | (+)(+) = +, (-)(-) = +, (+)(-) = – | (-3) × (-4) = 12 |
| Division | Same rules as multiplication | (-12) ÷ (-3) = 4 |
2. Exponents and Powers
| Concept | Formula | Explanation |
|---|---|---|
| Power | aⁿ = a × a × a … (n times) | a is base, n is exponent |
| Product Rule | aᵐ × aⁿ = aᵐ⁺ⁿ | Add exponents with same base |
| Quotient Rule | aᵐ ÷ aⁿ = aᵐ⁻ⁿ | Subtract exponents with same base |
| Power of Power | (aᵐ)ⁿ = aᵐⁿ | Multiply exponents |
| Zero Exponent | a⁰ = 1 | Any number to power zero is 1 |
| Negative Exponent | a⁻ⁿ = 1/aⁿ | Negative exponent means reciprocal |
3. Algebraic Expressions
| Identity | Formula | Expansion |
|---|---|---|
| Identity 1 | (a + b)² | a² + 2ab + b² |
| Identity 2 | (a – b)² | a² – 2ab + b² |
| Identity 3 | (a + b)(a – b) | a² – b² |
| Identity 4 | (x + a)(x + b) | x² + (a + b)x + ab |
4. Simple Equations
| Type | Standard Form | Solution Method |
|---|---|---|
| Linear Equation | ax + b = c | x = (c – b)/a |
| Transposition | Move term across = sign | Change sign when moving |
5. Geometry – Lines and Angles
| Concept | Formula/Property | Value |
|---|---|---|
| Straight Angle | – | 180° |
| Right Angle | – | 90° |
| Acute Angle | – | Less than 90° |
| Obtuse Angle | – | Between 90° and 180° |
| Complementary Angles | a + b = 90° | Sum is 90° |
| Supplementary Angles | a + b = 180° | Sum is 180° |
| Vertically Opposite Angles | Equal | ∠1 = ∠3, ∠2 = ∠4 |
| Linear Pair | a + b = 180° | Adjacent angles on straight line |
6. Triangle Properties
| Property | Formula | Explanation |
|---|---|---|
| Sum of Angles | ∠A + ∠B + ∠C = 180° | Interior angles of triangle |
| Exterior Angle | Exterior angle = Sum of opposite interior angles | ∠ACD = ∠A + ∠B |
| Pythagorean Theorem | a² + b² = c² | For right-angled triangles |
7. Perimeter and Area (Extended)
| Shape | Perimeter | Area |
|---|---|---|
| Parallelogram | 2(a + b) | base × height = b × h |
| Rhombus | 4 × side | ½ × d₁ × d₂ (diagonals) |
| Trapezium | a + b + c + d | ½(a + b) × h |
8. Simple Interest
| Concept | Formula | Variables |
|---|---|---|
| Simple Interest | SI = (P × R × T)/100 | P = Principal, R = Rate, T = Time |
| Amount | A = P + SI | Total amount after interest |
| Principal | P = (SI × 100)/(R × T) | Original amount |
| Rate | R = (SI × 100)/(P × T) | Interest rate percentage |
| Time | T = (SI × 100)/(P × R) | Time period |
Class 8 Mathematics Formulas
1. Rational Numbers
| Property | Formula | Explanation |
|---|---|---|
| Rational Number | p/q where q ≠ 0 | Can be expressed as fraction |
| Addition | a/b + c/d = (ad + bc)/bd | Common denominator method |
| Multiplication | a/b × c/d = ac/bd | Multiply numerators and denominators |
| Additive Identity | a/b + 0 = a/b | Zero is additive identity |
| Multiplicative Identity | a/b × 1 = a/b | One is multiplicative identity |
2. Squares and Square Roots
| Concept | Formula | Example |
|---|---|---|
| Perfect Square | n² | 5² = 25 |
| Square Root | √n | √25 = 5 |
| Pythagorean Triplet | a² + b² = c² | 3, 4, 5 or 5, 12, 13 |
| Property 1 | √(a × b) = √a × √b | √(4 × 9) = 2 × 3 = 6 |
| Property 2 | √(a/b) = √a/√b | √(25/4) = 5/2 |
3. Cubes and Cube Roots
| Concept | Formula | Example |
|---|---|---|
| Perfect Cube | n³ | 3³ = 27 |
| Cube Root | ∛n | ∛27 = 3 |
| Sum of Cubes | a³ + b³ = (a + b)(a² – ab + b²) | – |
| Difference of Cubes | a³ – b³ = (a – b)(a² + ab + b²) | – |
4. Algebraic Identities (Extended)
| Identity | Formula | Expansion |
|---|---|---|
| Identity 5 | (a + b)³ | a³ + b³ + 3ab(a + b) |
| Identity 6 | (a – b)³ | a³ – b³ – 3ab(a – b) |
| Identity 7 | a³ + b³ | (a + b)(a² – ab + b²) |
| Identity 8 | a³ – b³ | (a – b)(a² + ab + b²) |
| Identity 9 | (a + b + c)² | a² + b² + c² + 2ab + 2bc + 2ca |
5. Direct and Inverse Proportion
| Type | Formula | Relationship |
|---|---|---|
| Direct Proportion | x₁/y₁ = x₂/y₂ or x/y = k | If x increases, y increases |
| Inverse Proportion | x₁y₁ = x₂y₂ or xy = k | If x increases, y decreases |
6. Compound Interest
| Concept | Formula | Explanation |
|---|---|---|
| Amount | A = P(1 + R/100)ⁿ | Compounded annually |
| Compound Interest | CI = A – P | Difference between amount and principal |
| Half-Yearly Compounding | A = P(1 + R/200)²ⁿ | Compounded twice a year |
| Quarterly Compounding | A = P(1 + R/400)⁴ⁿ | Compounded four times a year |
7. Mensuration – Surface Areas and Volumes
| Shape | Total Surface Area | Volume |
|---|---|---|
| Cube | 6a² | a³ |
| Cuboid | 2(lb + bh + hl) | l × b × h |
| Cylinder | 2πr(r + h) | πr²h |
| Cone | πr(r + l) where l = slant height | ⅓πr²h |
| Sphere | 4πr² | ⁴⁄₃πr³ |
| Hemisphere | 3πr² | ⅔πr³ |
8. Quadrilaterals
| Shape | Area Formula | Special Properties |
|---|---|---|
| Square | side² = a² | All sides equal, all angles 90° |
| Rectangle | length × breadth = l × b | Opposite sides equal, all angles 90° |
| Parallelogram | base × height = b × h | Opposite sides parallel and equal |
| Rhombus | ½ × d₁ × d₂ | All sides equal, diagonals perpendicular |
| Trapezium | ½(a + b) × h | One pair of parallel sides |
Class 9 Mathematics Formulas
1. Number System (Real Numbers)
| Type | Definition | Examples |
|---|---|---|
| Natural Numbers (N) | Counting numbers | 1, 2, 3, 4, … |
| Whole Numbers (W) | Natural numbers + 0 | 0, 1, 2, 3, … |
| Integers (Z) | Whole numbers + negatives | …, -2, -1, 0, 1, 2, … |
| Rational Numbers (Q) | p/q form where q ≠ 0 | 2/3, -5/7, 0.5 |
| Irrational Numbers | Non-terminating, non-repeating | √2, π, e |
| Real Numbers (R) | Rational + Irrational | All numbers on number line |
2. Polynomials
| Concept | Formula | Degree |
|---|---|---|
| Linear | ax + b | 1 |
| Quadratic | ax² + bx + c | 2 |
| Cubic | ax³ + bx² + cx + d | 3 |
| Remainder Theorem | p(a) = remainder when p(x) divided by (x – a) | – |
| Factor Theorem | If p(a) = 0, then (x – a) is a factor | – |
3. Algebraic Identities (Complete Set)
| Identity | Formula |
|---|---|
| 1 | (a + b)² = a² + 2ab + b² |
| 2 | (a – b)² = a² – 2ab + b² |
| 3 | a² – b² = (a + b)(a – b) |
| 4 | (a + b)³ = a³ + b³ + 3ab(a + b) |
| 5 | (a – b)³ = a³ – b³ – 3ab(a – b) |
| 6 | a³ + b³ = (a + b)(a² – ab + b²) |
| 7 | a³ – b³ = (a – b)(a² + ab + b²) |
| 8 | (x + a)(x + b) = x² + (a + b)x + ab |
| 9 | (a + b + c)² = a² + b² + c² + 2ab + 2bc + 2ca |
4. Linear Equations in Two Variables
| Concept | Formula | Explanation |
|---|---|---|
| Standard Form | ax + by + c = 0 | Linear equation in two variables |
| Slope-Intercept Form | y = mx + c | m is slope, c is y-intercept |
| Point-Slope Form | y – y₁ = m(x – x₁) | Line through (x₁, y₁) with slope m |
| Two-Point Form | (y – y₁)/(y₂ – y₁) = (x – x₁)/(x₂ – x₁) | Line through two points |
5. Coordinate Geometry
| Concept | Formula | Explanation |
|---|---|---|
| Distance Formula | d = √[(x₂ – x₁)² + (y₂ – y₁)²] | Distance between two points |
| Section Formula | x = (mx₂ + nx₁)/(m + n), y = (my₂ + ny₁)/(m + n) | Point dividing line in ratio m:n |
| Midpoint Formula | x = (x₁ + x₂)/2, y = (y₁ + y₂)/2 | Midpoint of line segment |
| Area of Triangle | ½ | x₁(y₂ – y₃) + x₂(y₃ – y₁) + x₃(y₁ – y₂) |
6. Euclid’s Geometry
| Concept | Statement |
|---|---|
| Euclid’s Division Lemma | a = bq + r where 0 ≤ r < b |
| Euclid’s Algorithm | HCF(a, b) = HCF(b, r) where a = bq + r |
7. Triangles
| Concept | Formula/Theorem |
|---|---|
| Heron’s Formula | Area = √[s(s-a)(s-b)(s-c)] where s = (a+b+c)/2 |
| Congruency (SSS) | Three sides equal |
| Congruency (SAS) | Two sides and included angle equal |
| Congruency (ASA) | Two angles and included side equal |
| Congruency (RHS) | Right angle, hypotenuse, one side equal |
8. Circles
| Concept | Formula | Explanation |
|---|---|---|
| Circumference | 2πr | Perimeter of circle |
| Area | πr² | Space inside circle |
| Length of Arc | (θ/360°) × 2πr | θ is central angle |
| Area of Sector | (θ/360°) × πr² | Pie-shaped region |
| Area of Segment | Area of sector – Area of triangle | Region between chord and arc |
9. Surface Areas and Volumes (Advanced)
| Shape | Curved Surface Area | Total Surface Area | Volume |
|---|---|---|---|
| Sphere | 4πr² | 4πr² | ⁴⁄₃πr³ |
| Hemisphere | 2πr² | 3πr² | ⅔πr³ |
| Cone | πrl | πr(l + r) | ⅓πr²h |
| Cylinder | 2πrh | 2πr(r + h) | πr²h |
| Frustum of Cone | πl(r₁ + r₂) | π[r₁² + r₂² + l(r₁ + r₂)] | ⅓πh(r₁² + r₂² + r₁r₂) |
10. Statistics
| Concept | Formula | Explanation |
|---|---|---|
| Mean | x̄ = Σx/n | Average of observations |
| Median | Middle value when arranged | For odd n: (n+1)/2th term |
| Mode | Most frequently occurring value | Value with highest frequency |
| Range | Maximum – Minimum | Spread of data |
11. Probability
| Concept | Formula | Range |
|---|---|---|
| Probability | P(E) = (Number of favorable outcomes)/(Total number of outcomes) | 0 ≤ P(E) ≤ 1 |
| Certain Event | P(E) = 1 | Always occurs |
| Impossible Event | P(E) = 0 | Never occurs |
| Complementary Events | P(E) + P(not E) = 1 | Sum equals 1 |
Class 10 Mathematics Formulas
1. Real Numbers (Advanced)
| Concept | Formula/Theorem | Application |
|---|---|---|
| Fundamental Theorem of Arithmetic | Every composite number can be expressed as product of primes uniquely | Prime factorization |
| HCF × LCM | HCF(a,b) × LCM(a,b) = a × b | For two numbers |
| Rational Number Property | p/q is terminating if q = 2ᵐ × 5ⁿ | Decimal expansion |
2. Quadratic Equations
| Concept | Formula | Explanation |
|---|---|---|
| Standard Form | ax² + bx + c = 0 | a ≠ 0 |
| Quadratic Formula | x = [-b ± √(b² – 4ac)]/2a | Solutions of quadratic equation |
| Discriminant | D = b² – 4ac | Determines nature of roots |
| Nature of Roots (D > 0) | Two distinct real roots | Unequal roots |
| Nature of Roots (D = 0) | Two equal real roots | Equal roots |
| Nature of Roots (D < 0) | No real roots | Complex roots |
| Sum of Roots | α + β = -b/a | Relationship between roots and coefficients |
| Product of Roots | αβ = c/a | Relationship between roots and coefficients |
| Forming Equation | x² – (sum of roots)x + (product of roots) = 0 | When roots are given |
3. Arithmetic Progression (AP)
| Concept | Formula | Variables |
|---|---|---|
| nth Term | aₙ = a + (n-1)d | a = first term, d = common difference |
| Sum of n Terms | Sₙ = n/2[2a + (n-1)d] | When first term and common difference known |
| Sum of n Terms (alternate) | Sₙ = n/2(a + l) | When first and last terms known |
| Common Difference | d = a₂ – a₁ | Difference between consecutive terms |
4. Coordinate Geometry (Advanced)
| Concept | Formula | Application |
|---|---|---|
| Distance Formula | d = √[(x₂-x₁)² + (y₂-y₁)²] | Distance between two points |
| Section Formula (Internal) | P(x,y) = [(mx₂+nx₁)/(m+n), (my₂+ny₁)/(m+n)] | Point dividing line internally in m:n |
| Section Formula (External) | P(x,y) = [(mx₂-nx₁)/(m-n), (my₂-ny₁)/(m-n)] | Point dividing line externally in m:n |
| Midpoint Formula | M = [(x₁+x₂)/2, (y₁+y₂)/2] | Middle point of line segment |
| Area of Triangle | A = ½ | x₁(y₂-y₃) + x₂(y₃-y₁) + x₃(y₁-y₂) |
| Collinearity Condition | Area = 0 | Three points are collinear if area = 0 |
5. Triangles (Similarity)
| Concept | Theorem/Criteria | Statement |
|---|---|---|
| Basic Proportionality Theorem (Thales) | If a line parallel to one side intersects other two sides | It divides them proportionally |
| AA Similarity | Two angles equal | Triangles are similar |
| SSS Similarity | Three sides proportional | Triangles are similar |
| SAS Similarity | Two sides proportional and included angle equal | Triangles are similar |
| Pythagoras Theorem | a² + b² = c² | For right-angled triangles |
| Converse of Pythagoras | If a² + b² = c², then triangle is right-angled | – |
6. Circles (Advanced)
| Concept | Formula/Theorem | Explanation |
|---|---|---|
| Length of Tangent | √(d² – r²) | d = distance from center to external point |
| Tangent Property | Tangent ⊥ Radius at point of contact | Perpendicular relationship |
| Two Tangents from External Point | PA = PB | Equal lengths from external point |
| Angle between Tangent and Chord | Equal to angle in alternate segment | Alternate segment theorem |
7. Trigonometry
| Ratio | Formula | Reciprocal |
|---|---|---|
| sine | sin θ = Perpendicular/Hypotenuse | cosec θ = 1/sin θ |
| cosine | cos θ = Base/Hypotenuse | sec θ = 1/cos θ |
| tangent | tan θ = Perpendicular/Base | cot θ = 1/tan θ |
8. Trigonometric Identities
| Identity | Formula |
|---|---|
| Fundamental Identity | sin²θ + cos²θ = 1 |
| Identity 2 | 1 + tan²θ = sec²θ |
| Identity 3 | 1 + cot²θ = cosec²θ |
9. Trigonometric Ratios of Standard Angles
| Angle | 0° | 30° | 45° | 60° | 90° |
|---|---|---|---|---|---|
| sin θ | 0 | 1/2 | 1/√2 | √3/2 | 1 |
| cos θ | 1 | √3/2 | 1/√2 | 1/2 | 0 |
| tan θ | 0 | 1/√3 | 1 | √3 | ∞ |
| cot θ | ∞ | √3 | 1 | 1/√3 | 0 |
| sec θ | 1 | 2/√3 | √2 | 2 | ∞ |
| cosec θ | ∞ | 2 | √2 | 2/√3 | 1 |
10. Trigonometric Ratios of Complementary Angles
| Identity | Formula |
|---|---|
| sin(90° – θ) | cos θ |
| cos(90° – θ) | sin θ |
| tan(90° – θ) | cot θ |
| cot(90° – θ) | tan θ |
| sec(90° – θ) | cosec θ |
| cosec(90° – θ) | sec θ |
11. Heights and Distances
| Concept | Definition | Formula |
|---|---|---|
| Angle of Elevation | Angle above horizontal | tan θ = height/distance |
| Angle of Depression | Angle below horizontal | tan θ = height/distance |
12. Statistics (Advanced)
| Concept | Formula | For Grouped Data |
|---|---|---|
| Mean | x̄ = Σfx/Σf | Direct method |
| Mean (Assumed Mean) | x̄ = a + Σfd/Σf | Where d = x – a |
| Mean (Step Deviation) | x̄ = a + (Σfu/Σf) × h | Where u = (x-a)/h |
| Median | l + [(n/2 – cf)/f] × h | l = lower boundary, cf = cumulative frequency |
| Mode | l + [(f₁-f₀)/(2f₁-f₀-f₂)] × h | l = lower boundary of modal class |
13. Probability (Advanced)
| Concept | Formula | Explanation |
|---|---|---|
| Theoretical Probability | P(E) = Number of favorable outcomes / Total outcomes | Based on theory |
| Experimental Probability | P(E) = Number of times event occurred / Total trials | Based on experiment |
| Sum of Probabilities | P(E) + P(Ē) = 1 | Complementary events |
14. Surface Areas and Volumes (Combinations)
| Concept | Formula | Application |
|---|---|---|
| Combination of Solids | Total Surface Area = Sum – Common Area | When two solids joined |
| Volume of Combination | Total Volume = Sum of individual volumes | Adding volumes |
| Conversion | 1 m³ = 1000 liters | Volume to capacity |
Important Constants
| Constant | Symbol | Value (approx.) |
|---|---|---|
| Pi | π | 3.14159 or 22/7 |
| Euler’s Number | e | 2.71828 |
| Golden Ratio | φ | 1.61803 |
Units and Conversions
| Quantity | SI Unit | Common Conversions |
|---|---|---|
| Length | meter (m) | 1 km = 1000 m, 1 m = 100 cm |
| Area | square meter (m²) | 1 hectare = 10,000 m² |
| Volume | cubic meter (m³) | 1 m³ = 1000 liters |
| Time | second (s) | 1 hour = 3600 s |
| Speed | meter/second (m/s) | 1 km/h = 5/18 m/s |
Conclusion
This comprehensive guide covers all essential mathematics formulas from Class 6 to Class 10, organized systematically for easy reference. Regular practice with these formulas, combined with conceptual understanding, will build a strong mathematical foundation. Remember that formulas are tools understanding when and how to apply them is as important as memorizing them.
For best results, students should practice problems from textbooks, solve worksheets, and attempt sample papers regularly. This guide serves as a quick reference during revision and exam preparation.
Note: While this guide is comprehensive, students should always refer to their NCERT textbooks and consult teachers for detailed explanations and additional practice problems.
FAQs on Maths Formulas for Class 6 to 10
Q. What are the most important maths formulas for Class 6?
The most important maths formulas for Class 6 include:
Basic Arithmetic & Number System:
- Even numbers: 2n (where n is any integer)
- Odd numbers: 2n + 1
Fractions & Decimals:
- Addition of fractions: a/b + c/d = (ad + bc)/bd
- Multiplication of fractions: a/b × c/d = (a × c)/(b × d)
Ratio & Percentage:
- Percentage = (Value/Total) × 100%
- Ratio: a : b or a/b
Geometry – Area & Perimeter:
- Square: Perimeter = 4s, Area = s²
- Rectangle: Perimeter = 2(l + b), Area = l × b
- Triangle: Area = ½ × base × height
- Circle: Circumference = 2πr, Area = πr²
Q. How can I remember all maths formulas easily?
Here are proven techniques to memorize maths formulas effectively:
1. Understanding over Memorization:
- Learn how formulas are derived rather than rote learning
- Understand the logic behind each formula
2. Practice Daily:
- Solve 5-10 problems daily using different formulas
- Application helps retention better than reading
3. Create Visual Aids:
- Make colorful formula charts for your study room
- Use flashcards for quick revision
- Draw diagrams for geometry formulas
4. Use Mnemonics:
- For trigonometry: “Some People Have Curly Brown Hair Through Proper Brushing” (sin = P/H, cos = B/H, tan = P/B)
- Create your own memory tricks for complex formulas
5. Group Similar Formulas:
- Organize by topic (algebra, geometry, mensuration)
- Study related formulas together
6. Regular Revision:
- Review formulas weekly, not just before exams
- Use spaced repetition technique
7. Teach Others:
- Explain formulas to classmates or family members
- Teaching reinforces your own understanding
8. Make Formula Sheets:
- Create separate sheets for each chapter
- Keep them handy during homework and revision
Q. Where can I download maths formulas PDF for Class 6 to 10?
You can access maths formulas PDFs from several reliable sources:
Official & Educational Resources:
- NCERT Official Website (www.ncert.nic.in)
- Free textbooks with all formulas
- Chapter-wise PDFs available
- Most authentic source for CBSE students
- School Websites
- Many schools provide formula sheets
- Check your school’s academic resources section
- Educational Platforms:
- BYJU’S, Khan Academy, Vedantu
- Offer free downloadable formula PDFs
- Often include solved examples
- Government Educational Portals:
- DIKSHA platform
- State education board websites
What to Look For in a Good Formula PDF:
- Organized by class and chapter
- Clear explanations with examples
- Includes all NCERT topics
- Easy-to-read formatting
- Printable format
Q. What is the difference between Class 9 and Class 10 maths formulas?
Class 9 and Class 10 maths formulas differ significantly in complexity and application:
Class 9 Maths Formulas:
Foundation Building:
- Introduction to coordinate geometry (distance formula, section formula)
- Basic polynomial identities
- Heron’s formula for triangle area
- Simple surface area and volume formulas
- Basic trigonometric ratios (sin, cos, tan)
- Introduction to statistics (mean, median, mode)
- Basic probability concepts
Class 10 Maths Formulas:
Advanced Applications:
- Quadratic Equations: Complete formula including discriminant (D = b² – 4ac)
- Arithmetic Progressions: nth term and sum formulas
- Advanced Coordinate Geometry: Section formula (internal & external division)
- Trigonometry: All six ratios, identities (sin²θ + cos²θ = 1), complementary angles
- Standard trigonometric values: For 0°, 30°, 45°, 60°, 90°
- Advanced Statistics: Formulas for grouped data, median, mode calculations
- Circle Theorems: Tangent properties, length of tangent formula
- Similar Triangles: Proportionality theorems
Differences:
| Aspect | Class 9 | Class 10 |
|---|---|---|
| Complexity | Introductory level | Advanced, board exam level |
| Trigonometry | Basic 3 ratios | All 6 ratios + identities |
| Algebra | Simple polynomials | Quadratic equations |
| Statistics | Ungrouped data | Grouped data with frequency |
| Application | Conceptual understanding | Problem-solving for exams |
Q. Which algebraic identities are most important for board exams?
The following algebraic identities are crucial for board exams (Classes 9-10) and appear frequently:
Top 8 Essential Identities:
1. Square of Sum:
- (a + b)² = a² + 2ab + b²
- Most frequently used in expansions and factorization
2. Square of Difference:
- (a – b)² = a² – 2ab + b²
- Common in simplification problems
3. Difference of Squares:
- a² – b² = (a + b)(a – b)
- Used extensively in factorization
4. Cube of Sum:
- (a + b)³ = a³ + b³ + 3ab(a + b)
- Alternative form: a³ + 3a²b + 3ab² + b³
5. Cube of Difference:
- (a – b)³ = a³ – b³ – 3ab(a – b)
- Alternative form: a³ – 3a²b + 3ab² – b³
6. Sum of Cubes:
- a³ + b³ = (a + b)(a² – ab + b²)
- Important for factorization questions
7. Difference of Cubes:
- a³ – b³ = (a – b)(a² + ab + b²)
- Frequently asked in board exams
8. Square of Trinomial:
- (a + b + c)² = a² + b² + c² + 2ab + 2bc + 2ca
- Appears in complex algebraic problems
Q. How to prepare mensuration formulas for Class 8 to 10?
A comprehensive strategy to master mensuration formulas:
Step 1: Understand the Basics (Class 8 Level)
2D Shapes:
- Square, Rectangle, Triangle, Circle
- Parallelogram, Rhombus, Trapezium
- Focus on area and perimeter
3D Shapes:
- Cube, Cuboid, Cylinder
- Learn surface area (curved, total) and volume
Step 2: Organized Formula Learning
Create a Formula Chart with 4 Columns:
| Shape | Curved/Lateral Surface Area | Total Surface Area | Volume |
|---|---|---|---|
| Cube | – | 6a² | a³ |
| Cuboid | 2h(l+b) | 2(lb+bh+hl) | l×b×h |
| Cylinder | 2πrh | 2πr(r+h) | πr²h |
| Cone | πrl | πr(l+r) | ⅓πr²h |
| Sphere | 4πr² | 4πr² | ⁴⁄₃πr³ |
| Hemisphere | 2πr² | 3πr² | ⅔πr³ |
Step 3: Advanced Concepts (Class 9-10)
Combination of Solids:
- Hemisphere on cylinder
- Cone attached to cylinder
- Formula: Total SA = Sum of individual SA – Common area
Frustum of Cone (Class 10):
- Volume = ⅓πh(r₁² + r₂² + r₁r₂)
- Curved Surface Area = πl(r₁ + r₂)
Step 4: Effective Practice Strategy
Visual Learning:
- Draw 3D shapes while writing formulas
- Label all dimensions clearly
- Understand which measurement is what (radius, height, slant height)
Smart Practice Tips:
- Solve 5 problems daily from each shape type
- Identify the shape in word problems carefully
- Make unit conversions confidently (cm to m, m³ to liters)
- Check units in your answer (area = cm², volume = cm³)
Common Mistakes to Avoid:
- Confusing radius with diameter
- Using wrong formula (curved vs. total surface area)
- Forgetting π value (use 22/7 or 3.14 as specified)
- Not converting units before calculation
Revision Technique:
- Week 1: 2D shapes
- Week 2: Basic 3D shapes (cube, cuboid, cylinder)
- Week 3: Advanced 3D shapes (cone, sphere)
- Week 4: Combination problems and frustum
Q. What are the basic trigonometry formulas for Class 10?
Complete guide to Class 10 trigonometry formulas:
Part 1: Basic Trigonometric Ratios
In a Right-Angled Triangle:
- sin θ = Perpendicular/Hypotenuse (P/H)
- cos θ = Base/Hypotenuse (B/H)
- tan θ = Perpendicular/Base (P/B)
Reciprocal Ratios:
- cosec θ = 1/sin θ = H/P
- sec θ = 1/cos θ = H/B
- cot θ = 1/tan θ = B/P
Part 2: Fundamental Trigonometric Identities
Three Main Identities (Must Memorize):
- sin²θ + cos²θ = 1
- Most important identity
- Used in 40% of trigonometry problems
- 1 + tan²θ = sec²θ
- Derived from Identity 1
- 1 + cot²θ = cosec²θ
- Also derived from Identity 1
Part 3: Standard Angles Values (Crucial for Board Exams)
| Angle | sin θ | cos θ | tan θ | cot θ | sec θ | cosec θ |
|---|---|---|---|---|---|---|
| 0° | 0 | 1 | 0 | ∞ | 1 | ∞ |
| 30° | 1/2 | √3/2 | 1/√3 | √3 | 2/√3 | 2 |
| 45° | 1/√2 | 1/√2 | 1 | 1 | √2 | √2 |
| 60° | √3/2 | 1/2 | √3 | 1/√3 | 2 | 2/√3 |
| 90° | 1 | 0 | ∞ | 0 | ∞ | 1 |
Memory Pattern for sin:
- √0/2, √1/2, √2/2, √3/2, √4/2 (for 0°, 30°, 45°, 60°, 90°)
- For cos: Reverse the pattern
Part 4: Complementary Angle Formulas
When two angles add up to 90° (complementary):
- sin(90° – θ) = cos θ
- cos(90° – θ) = sin θ
- tan(90° – θ) = cot θ
- cot(90° – θ) = tan θ
- sec(90° – θ) = cosec θ
- cosec(90° – θ) = sec θ
Part 5: Quotient Identities
- tan θ = sin θ/cos θ
- cot θ = cos θ/sin θ
Q. What is the quadratic formula and when should I use it?
Complete guide to the quadratic formula – one of the most important formulas in Class 10:
The Quadratic Formula:
For any quadratic equation ax² + bx + c = 0 (where a ≠ 0):
x = [-b ± √(b² – 4ac)] / 2a
This formula gives you both roots (solutions) of the quadratic equation.
Understanding the Components:
The Discriminant (D):
- D = b² – 4ac
- This determines the nature of roots
Nature of Roots Based on Discriminant:
| Discriminant Value | Nature of Roots | Example |
|---|---|---|
| D > 0 | Two distinct real roots | x² – 5x + 6 = 0 (D = 1) |
| D = 0 | Two equal real roots | x² – 4x + 4 = 0 (D = 0) |
| D < 0 | No real roots (imaginary) | x² + x + 1 = 0 (D = -3) |
When to Use the Quadratic Formula:
Use When:
- Factorization is difficult or impossible
- Example: x² + 5x + 3 = 0 (doesn’t factor easily)
- Asked specifically to use formula method
- Board exams often ask “solve by quadratic formula”
- Finding decimal/exact roots
- When precise values are needed
- Coefficients are large numbers
- Example: 7x² + 15x + 2 = 0
- When time is limited
- Formula method is faster than trial-and-error
Don’t Use When:
- Simple factorization is possible
- Example: x² – 5x + 6 = 0 → (x-2)(x-3) = 0
- Completing the square is easier
- Some problems are designed for this method
- Equation can be simplified first
- 2x² – 8x + 6 = 0 → x² – 4x + 3 = 0