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

5929 Views

See similar Maths A Level tutors

Related Maths A Level answers

All answers ▸

Find D when 8x^3-12x^2-2x+D is divided by 2x+1 when the remainder is -2


The curve, C has equation y = 2x^2 +5x +k. The minimum value of C is -3/4. Find the value of k.


Differentiate the equation 4x^5 + 2x^3 - x + 2


Find the coordinates of the stationary points of the curve 3x=y+6x+3


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