Prove the following ( sin x - cos x +1)/ (sin x + cos x -1) = 1 / (sec x - tan x )
Please do explain it ..reply as soon as possible....
Answers
Answered by
5
Answer:
( sin x - cos x +1)/ (sin x + cos x -1) = 1 / (sec x - tan x )
Step-by-step explanation:
( sin x - cos x +1)/ (sin x + cos x -1) = 1 / (sec x - tan x )
LHS =
( sin x - cos x +1)/ (sin x + cos x -1)
Multiplying & Dividing by (sin x + cos x + 1)
= {(Sin x+ 1)² - Cos²x } / { (sin x + cos x)² - 1² }
= (Sin²x + 1 + 2Sinx - Cos²x) / (sin²x + cos²x + 2SinxCosx - 1)
using sin²x + cos²x = 1 or 1 - cos²x = Sin²x
= (Sin²x + 2Sinx + Sin²x) / (1 + 2SinxCosx - 1)
= (2Sin²x + 2Sinx) /(2SinxCosx)
= (Sinx + 1) /Cosx
Multiplying & Dividing by 1 - Sinx
= (1 - Sin²x) /(Cosx (1 - Sinx))
= Cos²x/(Cosx (1 - Sinx))
= Cosx/(1 - Sinx)
= 1/(1/Cosx - Sinx/Cosx)
= 1/(Secx - tanx)
= RHS
QED
Proved
( sin x - cos x +1)/ (sin x + cos x -1) = 1 / (sec x - tan x )
Similar questions