Prove the equation below is an identity.
(1+sin x)/(1 - sin x) =2sec2x + 2sec x tan x - 1
I understand identity when it comes to basic equations but this one just goes past my head.
Thank you for whoever has time for this!
I think it's supposed to be "2sec^2x " on the right side
(1+sin x)/(1 - sin x) =2sec^2x + 2sec x tan x - 1
Multiply top/bottom on the left hand side by ( 1 + sinx)
[ 1 + sinx) (1 + sinx)] / [ (1 - sinx) (1 + sin x) ] = 2sec^2x + 2sec x tan x - 1
Simplify the LHS and remember that [ 1 = sec^2x - tan^2x]
[ 1 + 2sinx + sin^2x] / (cos^2x] = 2sec^2x + 2secxtanx - [ sec^2x - tan^2x]
[ 1 + 2sinx + sin^2x] / (cos^2x] = sec^2x + 2secxtanx + tan^2x
And, on the left, we can write :
1/cos^2x + [2sinx]/ [ cosx * cosx] + [ sin^2x / cos^2x]
sec^2x + 2[sinx/cosx] * [1/ cosx] + tan^2x
sec^2x + 2tanxsecx + tan^2x
sec^2x + 2secxtanx + tan^2x and this equals the RHS
I think it's supposed to be "2sec^2x " on the right side
(1+sin x)/(1 - sin x) =2sec^2x + 2sec x tan x - 1
Multiply top/bottom on the left hand side by ( 1 + sinx)
[ 1 + sinx) (1 + sinx)] / [ (1 - sinx) (1 + sin x) ] = 2sec^2x + 2sec x tan x - 1
Simplify the LHS and remember that [ 1 = sec^2x - tan^2x]
[ 1 + 2sinx + sin^2x] / (cos^2x] = 2sec^2x + 2secxtanx - [ sec^2x - tan^2x]
[ 1 + 2sinx + sin^2x] / (cos^2x] = sec^2x + 2secxtanx + tan^2x
And, on the left, we can write :
1/cos^2x + [2sinx]/ [ cosx * cosx] + [ sin^2x / cos^2x]
sec^2x + 2[sinx/cosx] * [1/ cosx] + tan^2x
sec^2x + 2tanxsecx + tan^2x
sec^2x + 2secxtanx + tan^2x and this equals the RHS