diketahui a = 1-sinx / 1+ sin (90°-x) dan b = 1-cosx / 1+ cos ( 90°-x ). Nilai a/b adalah?

sin (90-x)=cosx
cos (90-x)=sinx
maka
a=1-sinx/1+cosx
b=1-cosx/1+sin x
a/b=1-sinx/1+cosx * 1+sinx/1-cosx=1-sin^2x/1-cos^2x=cos^2x/sin^2x=cot^2x