" 1) "int_(0)^( pi/4)(dx)/(1+sin x)

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

" 0."int_(0)^( pi/4)(dx)/(2+sin^(2)x)=

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

int_(0)^(pi) dx/(1-sin x)=

int_(0)^(pi)(x sin x)/(1-sin x)dx=

int_(0)^( pi/4)(sin x-cos x)dx

int_(0)^(pi//4)e^(x)sin x dx =

int_(0)^( pi/4)sin|x|dx

int_(0)^(1)(tan^(-1)x)/(x)dx is equals to int_(0)^((pi)/(2))(sin x)/(x)dx(b)int_(0)^((pi)/(2))(x)/(sin x)dx(1)/(2)int_(0)^((pi)/(2))(sin x)/(x)dx(d)(1)/(2)int_(0)^((pi)/(2))(x)/(sin x)dx