(sec A + tan A) (1 − sin A) =
To find: (sec A + tan A) (1 − sin A)
Consider (sec A + tan A) (1 − sin A)
We know that
∵ (a + b) (a – b) = a2 – b2
∴
Also, sin2 A + cos2 A = 1 ⇒ 1 – sin2 A = cos2 A