Is f(x) = x³ a Bijective Function?
Yes, f(x) = x³ is a bijective function from R to R (both one-one and onto).
One-One (Injective) Test: If f(a) = f(b), then a³ = b³ Taking cube roots: a = b Therefore, different inputs always produce different outputs.
Onto (Surjective) Test: For any real number y, we can find x = ∛y such that f(x) = y Since every real number has a real cube root, the range equals the codomain R.
Graphical Insight: The cubic function passes the horizontal line test (one-one) and covers all y-values (onto), making it bijective.
Key Takeaways: