Question

Prove By induction that sinx + sin3x + sin5x +.... Sin(2n-1) =sin^2(nx)/sin3x

Answer 1

do as with all inductions.
show that it's true for n=1

sinx = sin^2(x)/sin3x
Nope, not true.

So, how about n=2?
sinx+sin3x = sin^2(2x)/sin3x
Nope.

Better fix this and come back.

Answer 2

In the denominator it should be sinx