The quadratic formula can be used to solve quadratic equations that will not factorise. You will need to learn this formula, as well as understanding how to use it.

The quadratic formula for a quadratic equation in the form of is:

Example

First, identify the value of , and . In this example, , and .

Substitute these values into the quadratic formula:

To calculate the decimal answers, work out each answer in turn on a calculator.

The first solution is (2 dp).

The second solution is (2 dp).

Question