If `int_(pi/4)^((3pi)/4) x/(1+sinx)dx=k(sqrt(2)-1)`, then `k`= (A) `0` (B) `pi` (C) `2pi` (D) none of these

int_(pi//4)^(3pi//4)(xsinx)/(1+sinx)dx

int_(-pi//4)^(pi//4)(dx)/((1+sinx))

int_(-pi//4)^(pi//4)|sinx|dx=(2-sqrt(2))

int_(0)^(pi)(x sinx)/((1+sinx))dx=pi((pi)/(2)-1)

sqrt(3)int_0^pi dx/(1+2sin^2x)= (A) -pi (B) 0 (C) pi (D) none of these

If int_(0)^(20)sqrt(1-cos pi x)dx=(10k sqrt(2))/(pi), then k is

int_-pi^(3pi) cot^-1(cotx)dx= (A) pi^2 (B) 2pi^2 (C) 3pi^2 (D) none of these

The value of the integral int_(-(3 pi)/(4))^((pi)/(4))((sin x+cos x)/(e^(x-(pi)/(4))+1))dx(A)0(B)1(C)2(D) none of these

If I=int_(-pi)^pi e^(sinx)/(e^(sinx)+e^(-sinx))dx , then I equals (A) pi/2 (B) 2pi (C) pi (D) pi/4

If int_0^pi x f(sinx) dx=A int_0^(pi/2) f(sinx)dx , then A is (A) pi/2 (B) pi (C) 0 (D) 2pi