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 ▸

How do I find the maxima and minima of f(x) = e^(x^2)?


Let R denote the region bounded by the curve y=x^3 and the lines x=0 and x=4. Find the volume generated when R is rotated 360 degrees about the x axis.


(a) Express 9x+11/(2x+3)(x-1) as partial fractions and (b) find the integral of 9x+11/(2x+3)(x-1) with respect to x


Differentiate arctan(x) with respect to x. Leave your answer in terms of x