Prove the following identity: `(1 + cos(x))/sin(x) + (sin(x))/(1+cos(x)) = (2)/(sinx)`

Asked on by foxwit

1 Answer | Add Yours

Top Answer

degeneratecircle's profile pic

degeneratecircle | High School Teacher | (Level 2) Associate Educator

Posted on

We'll start from the left side and manipulate it until we get the right side. First, we get a common denominator as follows:


` ` Now `(1+cosx)^2=1+2cosx+cos^2x,` and if we add the fractions we get

`(1+cosx)^2/(sinx(1+cosx))+(sin^2x)/(sinx(1+cosx))=(1+2cosx+cos^2x+sin^2x)/(sinx(1+cosx))` .

But `cos^2x+sin^2x=1,` so the last fraction is equal to


which completes the proof.

` `


We’ve answered 319,832 questions. We can answer yours, too.

Ask a question