How to Solve Quadratic Equations Using the Graphical Method (Mathematics Lesson)
How to Solve Quadratic Equations Using the Graphical MethodA quadratic equation can be solved by drawing the equation on a graph and seeing where the curve crosses the x-axis:
A Real Example of How to Solve Quadratic Equations Using the Graphical MethodQuestion: Solve the quadratic equation below using the graphical method.
x1 = -1
x2 = 3
The solution to the quadratic equation is x = -1 or x = 3.
A Real Example of How to Solve Quadratic Equations Using the Graphical MethodSometimes quadratic equations have repeated roots - that is the same number solves the quadratic equation twice..
The slider below shows how to solve a quadratic equation where there are repeated roots.
THE 3 CASES SEEN GRAPHICALLYThere are 3 possible cases for the roots of a quadratic equation.
- 2 real, distinct roots. Occurs when the curve crosses the x-axis in two places.
- 1 repeated root. Occurs when the curve touches the x-axis at one point.
- 2 complex roots. Occurs when the curve does not touch the x-axis at all.