-->

Some Applications Of Trigonometry

Question
CBSEENMA10008266

Prove the following identity:
left parenthesis secA minus tanA right parenthesis squared space left parenthesis 1 plus sinA right parenthesis space equals space 1 minus space sinA.


Solution

L.H.S. = left parenthesis secA minus tanA right parenthesis squared space left parenthesis 1 plus sinA right parenthesis
     space equals space open parentheses 1 over cosA minus sinA over cosA close parentheses squared space left parenthesis 1 plus sinA right parenthesis
equals space open parentheses fraction numerator 1 minus sinA over denominator cosA end fraction close parentheses squared space left parenthesis 1 plus sinA right parenthesis space equals space fraction numerator left parenthesis 1 minus sinA right parenthesis squared over denominator cos squared straight A end fraction left parenthesis 1 plus sinA right parenthesis
equals space fraction numerator left parenthesis 1 minus sinA right parenthesis squared over denominator 1 minus sin squared straight A end fraction left parenthesis 1 plus sinA right parenthesis space equals space fraction numerator left parenthesis 1 minus sinA right parenthesis squared space left parenthesis 1 plus sinA right parenthesis over denominator left parenthesis 1 minus sinA right parenthesis thin space left parenthesis 1 plus sinA right parenthesis end fraction
space equals space 1 minus sinA space equals space straight R. straight H. straight S.

Some More Questions From Some Applications of Trigonometry Chapter