How do you know how many roots a quadratic equation has?

To work out the number of roots a qudratic ax2​+bx+c=0 you need to compute the discriminant (b2​-4ac).

If the discrimant is less than 0, then the quadratic has no real roots.

If the discriminant is equal to zero then the quadratic has equal roosts.

If the discriminant is more than zero then it has 2 distinct roots.

LC

Related Maths A Level answers

All answers ▸

Show that x^2+6x+11 can be written in as (x+p)^2+q, where p and q are integers to be found.


I know how to integrate, but I still never see any real world example of it, so it is difficult to understand. Why is it useful?


7x+5y-3z =16, 3x-5y+2z=-8, 5x+3y-7z=0. Solve for x,y and z.


solve x^3+2x^2+x=0