Question

Evaluate : tan-1(√2 sin 3π÷4)​

Answer 1

Answer:

Let cos−1(√3/2) = y then

cos y = √3/2 = cos(π/6)

We know that the range of the principal value branch of cos-1 is [0, π]

and cos(π/6) = √3/2

Hence, the principal value of cos−1(√3/2) = π/6.