`int(cosx)/((1+cosx))dx=?`A. `x+"tan"(x)/(2)+C`B. `-x+"tan"(x)/(2)+C`C. `x-"tan"(x)/(2)+C`D. none of these

`int(cosx)/((1+cosx))dx=?`A. `x+"tan"(x)/(2)+C`B. `-x+"tan"(x)/(2)+C`C

1.	`int(cosx)/((1+cosx))dx=?`A. `x+"tan"(x)/(2)+C`B. `-x+"tan"(x)/(2)+C`C. `x-"tan"(x)/(2)+C`D. none of these
Answer» Correct Answer - C `I=int{((1+cos)-1)/((1+cosx))}=f{1-(1)/(1+cosx)}dx`. `intdx-int(dx)/(1+cosx)=x-int(dx)/(2cos^(2)((x)/(2)))=-(1)/(2)int"sec"^(2)(x)/(2)dx` `=x-(1)/(2)xx2xxintsec^(2)"dt,where"(x)/(2)=t` `=x-tantC=x-"tan"(x)/(2)+C`.