Write the principal value of cos^-1(cos 2π/3) + sin^-1(sin 2π/3).

Question

Write the principal value of cos^-1(cos \(\frac{2\pi}3\)) + sin^-1(sin \(\frac{2\pi}3\)).

Answer 1

We know that sin^-1 (sin θ) = π – θ, if θ ∈ [π/2, 3π/2] and cos^-1 (cos θ) = θ, if θ ∈ [0, π]