Question #b8301

1 Answer
Apr 9, 2016

sin(pi/4-x)/sin(pi/4+x)

Explanation:

For this expression, (cos x + sin x) is not zero. When# x = -pi/4 and x = 3pi/4, cos x + sin x = 0. .

(cos 2x)/(1+sin 2x)=(cos^2x-sin^2x)/(cos^2x+sin^2x+2sin x cos x)=((cos x-sin x)(cos x+sin x))/(cos x+sin x)^2=(cos x-sin x)/(cos x+sin x)
Divide numerator and denominator bysqrt2 and use sin(pi/4)=cos(pi/4)=1/sqrt2
A simplified form is sin(pi/4-x)/sin(pi/4+x).