Answer each of the following questions in one word or one sentence or as per exact requirement of the question:

Question

Answer each of the following questions in one word or one sentence or as per exact requirement of the question: Write the value of .

Philoid · Accepted Answer

Given sin^-1 (cos π/9)

We know that cos θ = sin (π/2 – θ)

= sin^-1 (sin (π/2 - π/9))

= sin^-1 (sin 7π/18)

We know that sin^-1 (sin θ) = θ

= 7π/18

∴ sin^-1 (cos π/9) = 7π/18