Question

Write the trigonometric expression as an algebraic expression in u.

cos (cot^-1 u)

Answer 1

Write the trigonometric expression as an algebraic expression in u.

tan (csc-1 u)

Answer 2

$$
\cos(\arccos(u))=\cfrac{u}{\sqrt{1+u^2}}
$$
This is why:

Then \(\cos \theta=\cfrac{u}{\sqrt{1+u^2}}\)