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

1 Answer
Apr 16, 2018

Answer:

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

Both the roots are Imaginary

Explanation:

#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/

#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