Integrate y with respect to x, where y = cos(x)/[1+tan^2(x)]
y = cos(x)/sec2(x) = cos3(x)
y = cos(x)(1-sin2(x)) = cos(x) - cos(x) sin2(x)
-> sin(x) - sin3(x)/3 + c
DC
y = cos(x)/sec2(x) = cos3(x)
y = cos(x)(1-sin2(x)) = cos(x) - cos(x) sin2(x)
-> sin(x) - sin3(x)/3 + c
