Question

Which quadratic equation has no real roots?

Answer 1

Answer:

The first choice and the last have no real roots.

Step-by-step explanation:

For an equation to have no real roots the value of the discriminant ( b^2 - 4ac) will be negative.

Working out the values:

1.  D = (-2)^2 - 4* -1*-6 = -20 so it has no real roots.

2. D = (3)^2 - 4*  -2* 4 =  41 so it does have real roots.

3. D = (1)^2 - 4* 2*-6 = 49 so real roots.

4. D =   (-1)^2 - 4* 2*3 = -23 so  no real roots

Answer 2

Answer:

A and D

Step-by-step explanation:

By finding the roots of all the equations, we see that options A and D are the only ones that require an imaginary number in order to solve