Question

If cot x =3 then what is the answer of this?

`1/(1+cos x) + 1/(1-cos x) = ?`

Answer 1

20

Explanation:

Expression `E = 1/(1 + cos x) + 1/(1 - cos x) =`
`[(1 - cos x) + (1 + cos x)]/(1 - cos^2 x) = 2/sin^2 x`
Find `sin^2 x` by using trig identity:
`sin^2 x = 1/(1 + cot^2 x)`
In this case:
`sin ^2 x = 1/(1 + 9) = 1/10`
There for
`E = 2/(sin^2 x) = 20`