2.3: Solving quadratic equations using formula

Lesson Objective(s):

You should be able to

• identify values of a, b and c in a quadratic equation

• use the quadratic formula to solve quadratic equation

Always look through all examples in textbook before lesson.

Steps:

1. Check that the highest power is 2 for the variable.  

2. There may be a need to expand to get highest power two.  

       Eg: y(y -2) = 3; (p -2)(p + 1) = 10.

3. Ensure that one side of the equation is equals to zero

4. Identify the values of a, b and c (refer to video)

a = coefficient of x square

b = coefficient of x

c = constant

4. Substitute the values into the quadratic formula

5. Once you simplify, separate the fraction.

6. Evaluate each fraction

7. You must have 2 values for the variable as the answer, only special condition you may have one solution.

8. Check if you answer is correct by using your calculator

Using calculator to check answer for Quadratic Equations