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

5951 Views

See similar Maths A Level tutors

Related Maths A Level answers

All answers ▸

Find the equation of the straight line tangent to the curve y=2x^3+3x^2-4x+7, at the point x=-2.


The variable x=t^2 and the variable y=2t. What is dy/dx in terms of t?


Find the equation of the tangent of the curve y = (8x)/(x-8) at the point (0,0)


How do changes to the coefficient of x affect the graph y = f(x) as opposed to changes to the coefficient of f(x)?


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