Question

(sec A+ tan A)(1-sin A)=?
OPTIONS ARE:-
a) sec A
b) sin A
c) cosec A
d) cos A

Answer 1

Answer:

(secA+tanA)(1-sinA)

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

[(1+sinA)cosA](1-sinA)

(1+sinA)/cosA×1-sinA

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

(1^2-sinA^2)/cosA

1-sin^2A/cosA

cos^2A/cosA (sin^2A+cos^2A=1)

cosA

Answer 2

Answer:

option d)

Step-by-step explanation:

(secA+tanA)(1-sinA)=cosA

LHS:

1-secA=tanA ; tanA+secA=1

1-sinA=cosA

so,

substitute,

1*cosA=cosA

∴LHS=RHS