How do I find the root of a quadratic equation?

Usually the easiest way to find the root of a quadratic is to factorise it so you have something a form similar to - (x+2)(x-1)=0.

From here you need to find a value for x that makes each bracket equal to zero. Here we can see our answers are x = 1 and x = -2.

If the equation cannot be factorised our backup method that is slightly more complicated but always correct is to use the quadratic equation. 

This is given as x = (-b ± (b2-4ac)1/2)/2a,

Where a, b and c come from your original quadratic as ax2+bx+c. 

NF
Answered by Nicky F. Maths tutor

5787 Views

See similar Maths A Level tutors

Related Maths A Level answers

All answers ▸

The circle (x-3)^2 +(x-2)^2 = 20 has centre C. Write down the radius of the circle and the coordinates of C.


y=4sin(kx) write down dy/dx.


Differentiate x^x


Find the derivative of f(x)= ln(|sin(x)|). Given that f(x) has a value for all x, state why the modulus is required.


We're here to help

contact us iconContact ustelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

MyTutor is part of the IXL family of brands:

© 2026 by IXL Learning