Algebraic proof (new GCSE 9-1 Maths)

This worksheet focuses on quadratic expressions where the question requires the candidate to show that the expression is always positive, never negative, etc.

There is an introductory activity where students practise thinking about expressions of the form ax^2 + b, or a(x-b)^2 + c - doing a quick sketch of the graph and then deciding whether they are always positive, never negative, always negative or never positive.

Next is a page of example proofs to work through with your class, followed by an exercise with 15 questions for your class to attempt themselves.

Fully worked solutions to the examples and the exercise are included.