(Q)/(34)int_(0)^( pi/2)(sin^(2)x)/((1+cos x)^(2))dx

int_(0)^( pi/2)(sin^(2)x)/(sin^(2)x+cos^(2)x)dx

int_(0)^( pi/2)(sin x)/(1+cos x)dx

int_(0)^( pi/2)sin^(2)x cos x dx

int_(0)^(pi/2)(sin^(2)x*cos x)dx=

int_(0)^( pi)sin^(3)x(1+2cos x)(1+cos x)^(2)dx

int_(0)^(pi//2) (sin x)/(1 +cos^2) dx .

int_(0)^(pi//2)(sin 2x)/(2+2sin^(2)x+cos^(2)x)dx=

int_(0)^( pi)(sin x)/(1+cos^(2)x)dx =

int_(0)^( pi/2)(sin x-cos x)/(1+sin x*cos x)*dx

If I_(1)=int_(0)^(pi//2)(cos^(2)x)/(1+cos^(2)x)dx,I_(2)=int_(0)^(pi//2)(sin^(2)x)/(1+sin^(2)x)dx , I_(3)=int_(0)^(pi//2)(1+2cos^(2)x.sin^(2)x)/(4+2cos^(2)xsin^(2)x)dx , then