Question

prove the following:
(sec A + tan A) (1 - sin A) = cos A​

Answer 1

Answer:

LHS

(1/cosA + sinA/cosA)(1-sinA). (secA=1/cosA. , tanA=sinA/cosA)

((1+sinA)/cosA)(1-sinA)

[(1+sinA)(1-sinA)]/cosA. ((a-b)(a+b)=a^2 -b^2)

1-sin^2 A/cosA. (1-sin^2A=cos^2A)

cos^2 A/cosA

cosA=RHS

hope it helps...