Quadratic Functions2

1
Quadratic Functions(2)

• Solving quadratic equations through factorising.
• Checking to see if a quadratic equation will
  factorise.

2
Solving through factorisation

• Solving a quadratic equation through
  factorisation is usually the first choice method
  as it is the easiest.

• However, not all quadratic equations factorise
  and if they dont, you need to use a different
  method.

3
Trick

• If you substitute the values of a, b and c into
  the expression b2 4ac and you get a square
  number then the equation definitely factorises,
  otherwise, it doesnt.

4
Trick an example

• a5 b14 c-3

b2 4ac
Discriminant
(14)2 4 x (5) x (-3)
196 (-60) 256
This is a square number, so quadratic does
factorise
5
Solving Quadratic Equations

• We will now look at solving quadratic equations
  using factorisation