`int(dx)/(1+e^(-x))` is equal toA. `1+e^(x)+c`B. `ln(1+e^(-x))+c`C. `ln(1+e^(x))+c`D. `2 ln (1+e^(-x))+c`

`int(dx)/(1+e^(-x))` is equal toA. `1+e^(x)+c`B. `ln(1+e^(-x))+c`C. `l

1.	`int(dx)/(1+e^(-x))` is equal toA. `1+e^(x)+c`B. `ln(1+e^(-x))+c`C. `ln(1+e^(x))+c`D. `2 ln (1+e^(-x))+c`
Answer» Correct Answer - C `int(dx)/(1+e^(-x))` `rArr int (e^(x))/(e^(x)+1)dx` Let `e^(x)+1=t` ` e^(x) dx = dt` `= int(dt)/(t)` `rArr log t + c rArr log(e^(x)+1)+c`