`int_0^oo(x dx)/((1+x)(1+x^2))` is equal to (A) `pi/4` (B) `pi/2` (C) `pi` (D) none of these"

int_0^oo(pi/(1+pi^2x^2)-1/(1+x^2))logxdx is equal to (a) -pi/2lnpi (b) 0 (c) pi/2ln2 (d) none of these

lim_(x->1)(1-x^2)/(sin2pix) is equal to (a) 1/(2pi) (b) -1/pi (c) (-2)/pi (d) none of these

The value of integral int_0^(1/sqrt3) (dx)/((1+x^2)sqrt(1-x^2)) must be (a) 3+2pi (b) 4-pi (c) 2+pi (d) none of these

("lim")_(xvecoo)"{"x+5")"tan^(-1)(x+5)-(x+1)tan^(-1)(x+1)} is equal to (a) pi (b) 2pi (c) pi/2 (d) none of these

(lim)_(xrarr0)(sin(picos^2x)/(x^2)) is equal to (a) -pi (b) pi (c) pi/2 (d) 1

int_(-pi//4)^(pi//4) \ (e^x sec^2 \ dx)/(e^(2x)-1) is equal to (i) 0 (ii) 2 (iii) e (iv)none of these

If f(x)=0 is a quadratic equation such that f(-pi)=f(pi)=0 and f(pi/2)=-(3pi^2)/4, then lim_(x->-pi)(f(x))/("sin"(sinx) is equal to (a) 0 (b) pi (c) 2pi (d) none of these

If x_1=2tan^(-1)((1+x)/(1-x)),x_2=sin^(-1)((1-x^2)/(1+x^2)) , where x in (0,1), then x_1+x_2 is equal to 0 (b) 2pi (c) pi (d) none of these

int_(-pi/2)^(pi/2)(e^(|sinx|)cosx)/(1+e^(tanx))dx is equal to (a) e+1 (b) 1-e (c) e-1 (d) none of these

int_(5/2)^5(sqrt((25-x^2)^3))/(x^4)dx is equal to (a) pi/6 (b) (2pi)/3 (c) (5pi)/6 (d) pi/3