Question

Verify the following identities
1. Cos3x over cosx=1-4sin^2 x
2.cosx-cosy over sinx+siny + sinx-siny over cosx+cosy=0

Answer 1

Helpppppppp

Answer 2

@psymon

Answer 3

for 2nd one
-2sinx+y/2.sinx-y/2 over 2sinx+y/2.cosx-y/2 + 2cosx+y/2.sinx-y/2 over 2cosx++y/2.cosx-y/2

Answer 4

which will be
-tanx-y/2 + tanx-y/2 = 0

Answer 5

Thanks

Answer 6

welcome