How do you complete the square?

Completing the square is taking an equation in the form a1x2+b1x+c1 and butting it into the form a2(x+b2)2+c2Let's try an example:x2+4x+5First step is to make sure the coefficient of x2 is 1. In this case it's already done.Secondly we half the coefficient of x, and put that number into our brackets:(x+2)2+const.= x2+4x+5Now if we expand the left hand side of the equation, we can work out what constant to put at the end(x+2)2= x2+4x+4, but we want x2+4x+5. To make this we add 1 as our constant.Final answer: x2+4x+5=(x+2)2+1(I would then go on to have them work through a couple of examples to check their basic understanding, before moving onto examples where coefficient of x2 is larger than 1, and where coefficient of x is odd or negative. In each case I would allow them to work it through themselves as much as possible and only prompt where necessary, since practice is the best way to solidify an idea.)

AB
Answered by Annabelle B. Maths tutor

2525 Views

See similar Maths GCSE tutors

Related Maths GCSE answers

All answers ▸

A car costs £1200 in a sale. It was reduced by 20%. What was the original price?


A rectangle has length 3x+6 and width 2x-5. The perimeter of the rectangle is 22cm. What is the value of x?


a x 10^4 + a x 10^2 = 24 240 where a is a number. Work out a x 10^4 - a x10^2 Give your answer in standard form.


F(X)= 4/(x-3) g(x)= (x+2)/x solve fg(a)= 1


We're here to help

contact us iconContact usWhatsapp logoMessage us on Whatsapptelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

© MyTutorWeb Ltd 2013–2025

Terms & Conditions|Privacy Policy
Cookie Preferences