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

Write the principal value of .

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]

Given

= π

1