(cos/1)/(1+(sin/cos)) where the 1's and the cos cancel out left with sinx for the first part, right?
d-glitch
After the first step, you will still have two terms on the LHS
One of them will be cos / (1 + sin/cos) The other will be similar.
But there is nothing to cancel out yet.
The two terms have to simplified [ Step 2]
Then combined [ Step 3]
At this point, you will be able to factor and cancel [ Step 4]
This should be a four line proof.