Question

Simplify:
(1+cot^2y)(cos2y + 1)

The first cot is squared, the second is not. Thanks!

Answer 1

the second one is cot or cos?

Answer 2

\[(1+cot^2y)(cos2y+1)\]or
\[(1+cot^2y)(cot2y+1)\]

Answer 3

the second one is cos

Answer 4

\[1+cot^2y = \frac{1}{sin^2y}\]
\[cos2y+1=2cos^2y\]
----------------------------
time them together to get \[\frac{2cos^2y}{sin^2y}=2cot^2y\]