Question

What is Sin( inverse COS 3/5)?

Answer 1

`4/5`

Explanation:

Let inverse `cos(3/5)`= `theta`, so that it is `cos^-1 (3/5)= theta`

That means `cos theta = 3/5`.

Now work out `sin theta = sqrt(1-cos^2 theta)= 4/5`

`theta = sin^-1 (4/5)`

`sin cos^-1 (3/5)= sin sin^-1 (4/5)= 4/5`