prove each identity

Question

1) (sec - cos) / tan = sin

2) (csc^2 - 1) / csc^2 = cos^2

3) (sin/csc) - 1 = -cos/sec

Answer 1

Hints:

sec-cos = 1/cos - cos = (1-cos^2)/cos

csc^2 cos^ = (1/sin^2)cos^2 = cot^2

sin/csc = sin^2 and cos/sec = cos^2