How do you solve and find the value of cos(cos1(22)π2)?

1 Answer
Apr 7, 2018

22

Explanation:

First, recall that cos(xπ2)=sinx, so here, we're truly being asked to find

sin(cos1(22))

Now, determine cos1(22).

x=cos1(22)cosx=22, from the definition of an inverse function.

Keeping in mind that the domain of the inverse cosine is [1,1], the only solution to the above equation is

x=π4

Thus, we get

sin(π4)=22