Question

rewrite the expression in terms of the given function. (1/1+sinx)+(sinx/1-sinx); secx

Answer 1

Use the common denominator. (1-sinx)(1+sinx)
Add the numerators, should get 1+sin^2x.
multiply out the bottom and then use the identity cos^2x+sin^2x=1.

top becomes 2-cos^2x and bottom becomes cos^2x. seperate them.

ans: 2sec^2 -1