Question

Question #90c7a

Answer 1

`- 2tan x.csc x`

Explanation:

`E = 1/(cos x + 1) + 1/(cos x - 1) =`
`= [(cos x - 1) + (cos x + 1)]/-(cos^2 x - 1) = - (2cos x)/(sin^2 x) =`
`E = -2tan x.csc x`