How do you find the discriminant for $x^2-9x+21=0$ and determine the number and type of solutions?

Question

4763 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2018-04-16T02:20:09

$color(crimson)("Discriminant " < 0, " given equation has " color(brown)("NO REAL ROOTS"$

Both the roots are Imaginary

$color(crimson)("Discriminant " < 0, " given equation has " color(brown)("NO REAL ROOTS"$

Standard form of quadratic equation is $ax^2 + bx + c = 0$

$x^2 -9x + 21$

![https://newcollegeswindonmaths.wordpress.com/2016/04/10/core-1-discriminant/]( useruploads.socratic.org )

$a = 1, b = -9, c = 21, D = b^2 - 4ac = (-9)^2 - (4 * 1 * 21) = -3$

Since $color(crimson)("Discriminant " < 0, " given equation has " color(brown)("NO REAL ROOTS"$

Both the roots are Imaginary

How do you find the discriminant for x^2-9x+21=0x^2-9x+21=0 and determine the number and type of solutions?