Question

How many real solutions are there for the following equation?

0=12x2+x−1
A
0

B
3

C
2

D
1

Answer 1

two real solutions (Answer C)

Explanation:

You can study the discriminator of this expression to find your answer.

Recall that the discriminator of a quadratic equation of the form:
`ax^2+bx+c=0` is:
`b^2-4ac`

So for this equation,
`a=12, \,b=1, \,and \,c=-1`

Therefore, the discriminator gives:
`(1)^2-4(12)(-1)=49` which is larger than zero.

This tells us that the equation has two real solutions.