Using Quadratic Graphs

Quadratic graphs

• You can use graphs to solve quadratic equations
• You will need to look for the x-values of the points where a quadratic graph intersects with a straight line

A suitable line

• To find a suitable straight line, rearrange the quadratic equation so that the left-hand side matches the equation of the quadratic graph
• The right-hand side will tell you which line to draw
• Here is another example
  • Graph given= y =x^2 -6x +4
  • Equation to solve = x^2 -5x +1 =0
  • Rearrange equation = x^2 - 6x +4 = -x + 3
  • Line to draw = y = -x +3