Question

What does `sec(arccos(2))+3cot(arctan(-1))` equal?

Answer 1

As absolute value of cos x = |cos x| `<=1`, there is no x for which cosine is 2.

Explanation:

If x = arc cos (2), cos x = 2 > 1.
So, arc cos(2) is unreal..

The second term = `3cot(arc cot(1/(-1))=3cot(arc cot(-1))=3(-1)=-3`

Successive operations by 'cot' over 'arc cot' amounts to multiplication by 1..