Question

How do you find the value of `cos^ -1(0)`?

Answer 1

`cos^{-1}0=pi/2`

Explanation:

graph{cosx [-7.855, 7.856, -3.93, 3.925]}

`cos^{-1}` is an angle `x`, for which `cos x=0`. If you look at the graph of `f(x)=cosx` you see that `cosx=0` for `x=pi/2+kpi` for any `k in ZZ`, so the smallest positive value is `pi/2`