What can I say about the roots of a quadratic equation without actually calculating them?

If a quadratic equation is of the form ax2+bx+c, calculate D (Discriminant) whose value is b2-4ac. 

If the value of D is negative, the equation has imaginary roots.

If the value of D is positive, the equation has real and distinct roots.

If the value of D is zero, the equation has real and equal roots.

SS
Answered by Swapnil S. Maths tutor

4673 Views

See similar Maths GCSE tutors

Related Maths GCSE answers

All answers ▸

Renee buys 5kg of sweets to sell. She pays £10 for the sweets. Renee puts all the sweets into bags. She puts 250g of sweets into each bag. She sells each bag of sweets for 65p. Renee sells all the bags of sweets. Work out her percentage profit.


simultaneous equations - 2x + y = 7 and 3x -y = 8


a)By completing the square, prove the quadratic formula starting from ax^2+bx+c=0, b) hence, or otherwise solve 3x^2 + 7x -2= 9, to 3s.f.


y is inversely proportional to d^2 and when d = 10, y = 4. d is directly proportional to x^2 and when x = 2, d = 24. Find a formula for y in terms of x. Give your answer in its simplest form.


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