`intcos{2tan^(-1)sqrt((1-x)/(1+x))}dx` is equal toA. `(1)/(8)(x^(2)-1)+C`B. `(x^(2))/(4)+C`C. `(x)/(2)+C`D. `(x^(2))/(2)+C`

`intcos{2tan^(-1)sqrt((1-x)/(1+x))}dx` is equal toA. `(1)/(8)(x^(2)-1)

1.	`intcos{2tan^(-1)sqrt((1-x)/(1+x))}dx` is equal toA. `(1)/(8)(x^(2)-1)+C`B. `(x^(2))/(4)+C`C. `(x)/(2)+C`D. `(x^(2))/(2)+C`
Answer» Correct Answer - D Let `l=intcos{2tan^(-1)sqrt((1-x)/(1+x))}dx` Put`" "x= cos theta,` then `l=int cos {2tan^(-1)sqrt((1-cos theta)/(1+cos theta))}dx` `=int cos{2tan^(-1)(tan.(theta)/(2))}dx` `=intcos theta dx=int xdx=(x^(2))/(2)+C`