What does it mean to "complete the square"?

Completing the square is a useful method of rearranging a quadratic equation so the unknown ("x") only appears in it once. The theory of completing the square tells us that we can take a quadratic equation: x2 + bx + c = 0 and rearrange it to give (x + b/2)2 + c - (b/2)2 =0. Sometimes this can help us solve the equation and sometimes it's just a useful result to have. We can explain why this rearranging works using geometry.

Answered by Caitlin G. Maths tutor

2554 Views

See similar Maths GCSE tutors

Related Maths GCSE answers

All answers ▸

Solve the simultaneous equations 2x - y = 13, x - 2y = 11


Write 2x^2 + 16x + 26 in the form a(x + d)^2 + e where a, d, and e are integers.


Show that the recurring decimal 0.0151515..=1/66 (4H)


Northern Bank has two types of account. Both accounts pay compound interest. Cash savings account: Interest 2.5% per annum Shares account: Interest 3.5% per annum Ali invests £2000 in the cash savings account. Ben invests £1600 in the shares account.


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 2013–2024

Terms & Conditions|Privacy Policy