" 21."int((1-x^(2)))/((1+x^(2)))dx=?

int((1+x))/((1+x^(2)))dx

int(x^(2)+x+1)/(x^(2)-x+1)dx

int(x^(2)-1)/(1-x)dx

int(1)/(1-x-x^(2))dx

int_(-1)^(1)(1-x^(2))/(1+x^(2))dx is

Evaluate: int_(1)^(2)(1)/((x+1)(x+2))dx( ii) int_(1)^(2)(1)/(x(1+x^(2)))dx

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

If I_(1) int sin^(-1) ((2x)/(1 +x^(2)) ) dx , I_(2) = int cos^(-1) ((1-x^(2))/(1 +x^(2)) ) dx , I_(3) = int tan^(-1) ((2x)/(1 - x^(2)) ) dx , then I_(1) + I_(2) - I_(3) =

"int_1^(2)((1)/(x)-(1)/(2x^(2)))dx

int (1-x^2)/(1+x)dx