How to prove this trigonometric identity?
Are you happy about these identities?
If so then proving identities, as above, is a matter of doing something and seeing where you get to!!!
LHS can be written
Multiply LHS and RHS by
Now looking at the LHS and remembering that
We are there!!!
Difficult for me to write this really clearly here, paper would be easier!!!
BUT THE IMPORTANT THING WITH IDENTITIES IS DO SOMETHING AND YOU WILL GET THERE.