What are the key features of quadratic graphs?

The value of?a?affects the shape of the curve

• • If?a?is?positive?the shape is?concave up?∪
  • If?a?is?negative?the shape is?concave down?∩
• The?y-intercept?is at the point (0,?c)
• 
  • These can be found by
    • Factorising
    • Quadratic formula
    • Using your GDC
  • These are also called the?x-intercepts
  • There can be 0, 1 or 2?x-intercepts
    • This is determined by the value of the?discriminant
  • If?a?is?positive?then the vertex is the?minimum point
  • If?a?is?negative?then the vertex is the?maximum point

What are the equations of a quadratic function?

How do I find an equation of a quadratic?