Maths4U
Menu

Cambridge 9709 · Pure Mathematics 1

Practise completing the square

Check your answers and use feedback to improve.

3 worked examples10 guided questionsFractions and negative coefficients

Maths4U Original: notes, examples & two exam-style problems

Your practice progress

10 questions to work through

Your practice history is kept on this device. You can try questions and see feedback without an account.

How to enter answers

Use integers, fractions such as -3/2, or decimals rounded to six decimal places. Keep the sign inside the bracket. For equations, work on paper first, then choose an answer.

Start with a unit coefficient

1

Complete the square

Not checked

Rewrite \(x^2+2x-5\) in the form \((x+p)^2+q\).

Enter the coefficients
Review the method

2

Complete the square

Not checked

Rewrite \(x^2-10x+20\) in the form \((x+p)^2+q\).

Enter the coefficients
Review the method

3

Complete the square

Not checked

Rewrite \(x^2-4x+1\) in the form \((x+p)^2+q\).

Enter the coefficients
Review the method

Keep the outside coefficient

4

Complete the square with a coefficient

Not checked

Rewrite \(6x^2+12x-3\) in the form \(a(x+b)^2+c\).

Enter the coefficients
Review the method

5

Complete the square with a coefficient

Not checked

Rewrite \(3x^2-6x-15\) in the form \(a(x+b)^2+c\).

Enter the coefficients
Review the method

6

Complete the square with a coefficient

Not checked

Rewrite \(3x^2+5x+1\) in the form \(a(x+b)^2+c\).

Enter the coefficients
Review the method

Handle a negative square

7

Complete the square

Not checked

Rewrite \(6-8x-x^2\) in the form \(q-(x+p)^2\).

Enter the coefficients
Review the method

8

Complete the square with a coefficient

Not checked

Rewrite \(5-2x-2x^2\) in the form \(c-a(x+b)^2\).

Enter the coefficients
Review the method

Use the form to solve equations

9

Solve by completing the square

Not checked

Solve \(x^2+6x+1=0\) by completing the square. Give your answers in surd form.

Choose the pair of roots
Review the method

10

Solve by completing the square

Not checked

Solve \(x^2-3x-2=0\) by completing the square. Give your answers in surd form.

Choose the pair of roots
Review the method

Keep practising

Open all 32 questions in this topicTry 22 exam questionsThe number of roots of a quadratic equation