trigonometry help me
posted by eddy .
6.Prove that tan y cos^2 y + sin^2y/sin y = cos y + sin y
10.Prove that 1+tanθ/1tanθ = sec^2θ+2tanθ/1tan^2θ
17.Prove that sin^2wcos^2w/tan w sin w + cos w tan w = cos wcot w cos w
23.Find a counterexample to shows that the equation sec a – cos a = sin a sec a is not an identity.

you gotta add some parentheses, so we can tell what's the numerator and what's the denominator.
For #23, just pick an easy value, like pi/4:
√2  1/√2 =?= 1/√2 * √2
No.