Thurs Apr 19th – Solving Quadratics that do not factorise – Competing the Square and Quadratic Formula

LEARNING OBJECTIVE: Discover other methods of solving quadratics when they will not factorise

SUCCESS CRITERIA: You will be able to solve quadratics that do not factorise.

Engagement Activity:

Use your calculator to write down the solution to the following problems to 2decimal places.

a. 3 - √23,    b. 3+ √23

a. 6 - √35,     b. 6+ √35

a. -33 - √41,     b. -3+ √41

a. -8 - √17,     b. -8+ √17

a. -9 - √75,     b. -9+ √75

Completing the square Calculator

LESSON:

Have 20 mins to try and complete these equations you started yesterday. Give the answers BOTH in surd form and the two solutions to 2dp.

1. x² + 14x – 5 = 0 , Complete this square (x + 7) ²
   
2. x² -6x + 3 = 0 , Complete this square (x - 3) ²
   
3. x² +6x + 7 = 0 , Complete this square (x + 3) ²
   
4. x² - 4x - 1 = 0 , Complete this square (x - 2) ²
   
5. x² + 3x + 3 = 0 , Complete this square (x + 1½ ) ²
   
6. x² - 5x – 5 = 0 , Complete this square (x – 2½)²
   
7. x² + x - 1 = 0 , Complete this square (x + ½)²
   
8. x² + 8x - 6 = 0 , Complete this square (x + 4) ²
   
9. x² + 2x -1 = 0 , Complete this square (x + 1) ²
   
10. x² -2x - 7 = 0 , Complete this square (x - 1) ²
    

Exam Questions

PLENARIES: Checking Answers throughout the lesson, feedback from Students on Confidence