Question

What is the inverse of cosine (-1/2)?

Answer 1

`cos^(-1)(-1/2) = (2pi)/3`

Explanation:

The inverse cos function (`cos^(-1)`) is restricted to a range of `[0,pi]`

If `theta = soc^(-1)(-1/2)`
then
`color(white)("XXXX")cos(theta) = -1/2`

The only angle within the range `[0,pi]` that satisfies this condition is pictured below: