Question
Class 11MathematicsTrigonometric Functions

Prove that:

cot(x) × cot(2x) − cot(2x) × cot(3x) − cot(3x) × cot(x) = 1

Verified Answer

cot(3x) = cot(2x + x)

cot(3x) = (cot(2x) × cot(x) − 1) / (cot(x) + cot(2x))

cot(3x) × cot(x) + cot(3x) × cot(2x) = cot(2x) × cot(x) − 1

cot(x) × cot(2x) − cot(2x) × cot(3x) − cot(3x) × cot(x) = 1