Question

If `y = sqrt((1 + tan x)/(1 - tan x)) " then " (dy)/(dx)=` ?
A. `(1)/(2) sec^(2)x.tan (x + (pi)/(4))`
B. `(sec^(2) (x + (pi)/(4)))/(2 sqrt(tan (x + (pi)/(4))))`
C. `(sec^(2) ((x)/(4)))/(sqrt(tan (x + (pi)/(4))))`
D. none of these

Answer 1

Correct Answer - B
`y = {tan (x + (pi)/(4))}^((1)/(2)) rArr (dy)/(dx) = (1)/(2) {tan (x + (pi)/(4))}^(-(1)/(2)).sec^(2) (x + (pi)/(4))`