Question

if cos 3x = 0 and x is acute, find the value of: (i) sin x,(ii) cos 2x, (iii) cot² x-cosec² x​

Answer 1

Answer:

Step-by-step explanation:

Cos3x = 0

=> Cos3x = Cos90°  ( ∵ Cos90° = 0)

=> 3x = 90

=> x = 90/3 = 30°.

So

1) Sin30 = 1/2

2) Cos2(30) = Cos60 = 1/2

3) Cot²60 - Cosesc²60 = - 1   (∵ as per identity, Cosec²θ - Cot²θ = 1)