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 .

Given sin^{-1} (-1/2)

We know that sin^{-1} (-θ) = -sin^{-1} (θ)

= - sin^{-1} (1/2)

= π/6

∴ sin^{-1} (-1/2) = π/6

1