Completing The Square
Now that you have learned how the completing the square formula is derived, we will go through three examples to help you apply the method step by step.
Related Lessons:
Example 1
Write the following equation in the form \(𝑎(𝑥+𝑏)^2+𝑐\)
- \(𝑥^2+4𝑥−6\)
- \(𝑥^2+5𝑥−6\)
- \(2𝑥^2+8𝑥+5\)
- \(4𝑥^2−8𝑥+6\)
Example 2
- Express \(𝑥^2+11𝑥−15\) in the form \((𝑥+𝑎)^2+𝑏\)
- Hence solve the equation \(𝑥^2+11𝑥−15=0\), giving your answers correct to two decimal places.
Example 3
- Express \(−𝑥^2+8𝑥+15 \) in the form \(a(𝑥+b)^2+c\)
- Hence solve the equation \(−𝑥^2+8𝑥+15=0\), giving your answers correct to two decimal places.