Question

I NEED HELP PLEASE, THANKS! :)

Answer 1

First option is the right choice.

Explanation:

`(1)/(\cos \left(x\right)+1)+(1)/(\cos \left(x\right)-1)\\\\(\cos \left(x\right)-1)/(\left(\cos \left(x\right)+1\right)\left(\cos \left(x\right)-1\right))+(\cos \left(x\right)+1)/(\left(\cos \left(x\right)+1\right)\left(\cos \left(x\right)-1\right))\\\\=(\cos \left(x\right)-1+\cos \left(x\right)+1)/(\left(\cos \left(x\right)+1\right)\left(\cos \left(x\right)-1\right))\\\\=(2cos\left(x\right))/(cos^2\left(x\right)-1)\\\\=(2cos\left(x\right))/(sin^2\left(x\right))`

`=2\cdot (cos\left(x\right))/(sin\left(x\right))\cdot (1)/(sin\left(x\right))\\\\=-2cot(x)csc(x)`

Best Regards!