If the discriminant of a quadratic equation is equal to -8, which statement describes the roots?
a.) there are two complex roots.
b.) there are two real roots.
c.) there is one real root.
d.) there is one complex root.

Keywords

quadratic equation, discriminant, complex roots, real roots

we know that

The formula to calculate the roots of the quadratic equation of the form   is equal to

where

The discriminant of the quadratic equation  is equal to

if   ----> the quadratic equation has two real roots

if   ----> the quadratic equation has one real root

if   ----> the quadratic equation has two complex roots

in this problem we have that

the discriminant is equal to

so

the quadratic equation has two complex roots

therefore

the answer is the option A

There are two complex roots

the answer is d. 75%

solution:

→c= a b , that is product of a and b is possible only when when a is m × n matrix and b is n × p matrix.

that is, number of columns of a= number of rows of b.

so, size of matrix , c= a b is , if a = (m × n)matrix

b= (n × p)matrix

then a b = [ (m × n)matrix] ×[   (n × p)matrix ]

→→c= a b= [m × p ] matrix

→→size of product a b will be equal to = number of rows of a × number of columns of b