Question

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

Answer 1

You can call v its value... Also remember that `cos^-1` is the same as `arccos`...

So, let's say that:

`v=arccos(-1)`

If this is the case, then:

`cos(v)=-1`

It turns out that:

`cos(pi)=-1`

Therefore, `v=pi` and this is your answer. You can check this result by looking at the `y=arccosx` graph below. When `x=-1`, `y=pi` which confirms that the result we've obtained is correct.

graph{y=arccosx [-10, 10, -5, 5]}