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

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

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

Prove that: int_(0)^( pi/2)(sin x)/(sin x-cos x)dx=(pi)/(4)

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

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

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

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

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

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

I_(1)=int_(0)^((pi)/(2))(sin x-cos x)/(1+sin x cos x)dx,I_(2)=int_(0)^(2 pi)cos^(6)xdx,I_(3)=int_((pi)/(2))^((pi)/(2))sin^(3)xdx,I_(4)=int_(0)^(1)1n((1)/(x)-1)dx. Then I_(1)=I_(3)=I_(4)=0,I_(1)!=0I_(1)=I_(3)=0,I_(4)!=0I_(1)=I_(2)=0,I_(4)!=0I_(1)=I_(2)=I_(3)=0,I_(4)!=0