Question

If sinA .tanA/cosA=9 than prove that
SinA=3/√10

Answer 1

sinA.tanA/cosA = 9
{sinA/cosA}.tanA = 9
tanA.tanA = 9
tan² A = 9
take square both sides,
tanA = ± 3

here we take tanA = 3 = 3/1 = p/b
we know, sinA = p/h
h = √(p² + b²) = √(3² + 1²) = √10

hence , sinA = p/h = 3/√10

Answer 2

The required answer is in the attachment.