Help me please~ Anyone?
Question:
Prove this identity.
1+cos2A-cos2B-cos2(A+B)=4sin(A+B)cosAcosB
HELP! I only able to proceed 1 step only, and then, it just go back to the question again when i further solving it! Dying...
Help me please~ Anyone?
Question:
Prove this identity.
1+cos2A-cos2B-cos2(A+B)=4sin(A+B)cosAcosB
HELP! I only able to proceed 1 step only, and then, it just go back to the question again when i further solving it! Dying...