Prove an identity

Steps

1. Start from one side, usually the more complicated one.
2. Expand and simplify until it equals the other side.
3. End with "∴ L.H.S. = R.H.S." Never move terms across the "≡".

For the whole topic, read Polynomials and factorisation: key points, common mistakes and how the DSE tests it.

Other methods in this topic