How do I find roots of a quadratic equation when I can't factorise?

When factorising isn't working, we can try using the quadratic formula. First, we need our quadratic equation and find a,b and c - the coefficients of x and the constant. Now, we can write out the quadratic formula and plug in the corresponding numbers. Remember there are two different answers given by this method. With a calculator this is nice and easy - just type it in and write the answer to 2/3 decimal places (if needed). Without a calculator we can just simplify as far as possible so we might still have a surd in the answer but that's OK.

Answered by Freya D. Maths tutor

3006 Views

See similar Maths GCSE tutors

Related Maths GCSE answers

All answers ▸

Determine if the Following equality has real roots: (3*X^2) - (2*X) + 4 = (5*X^2) + (3*X) + 9, If the equation has real roots, calculate the roots for this equation.


A,B and C all lie on the line x^2 + y^2 = 49 where A is on the y axis, B is on the X axis and C is the mid point of the straight-line connecting A and B.


A cylinder has a radius of 4 cm and volume of 800 cm3. A similar cylinder with the same height has a volume of 200 cm3. Find the radius of the smaller cylinder.


How do you solve linear algebraic equations?


We're here to help

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