Sketching Quadratics
By completing the square

Quadratics

Factorising when A = 0

• Sum and product method (part 1)
• Sum and product method (part 2)

Factorising when A ≠ 0

• Cross method (part 1)
• Cross method (part 2)

Factorising special situations​

• Factorising perfect squares
• Factorising difference of two squares (part 1)
• Factorising difference of two squares (part 2)
• ​Factorising by completing the square​

Solving quadratic equations

• Solving basic quadratics
• Null factor law
• Solution by factorisation
• Solution by completing the square
• The quadratic formula

Sketching quadratic equations

• From factorised form
• From vertex form (part 1)
• From vertex form (part 2)
• By completing the square​​

If a quadratic is given in general form, the quadratic can be sketched using the vertex and axes intercepts if it is first factorised by completing the square, hence rewriting it in vertex form.