if sin2x=3sin2y,

Question

prove that:
2tan(x-y)=tan(x+y)

Answer 1

Do you mean sin(2x) or sin^2(x) ?
Similarly, do you mean sin(2y) or sin^2 (y) ?

Answer 2

if sin2x=3sin2y,
prove that:
2tan(x-y)=tan(x+y)

( here, in sin2x, 2x is an angle., like there's a formula:sin2x=2sinxcosx and sin2y=2sinycosy; ....)