Question

a quadratic equation has a discriminant of 12. which could be the equation? a.0 = –x2 8x 2 b.0 = 2x2 6x 3 c.0 = –x2 4x 1 d.0 = 4x2 2x 1

Answer 1

d = b^2 - 4ac
For option a, d = 72
For option b, d = 12
The equation is 0 = 2x^2 + 6x + 3

Answer 2

Option b which is
`2x^2+6x+3=0`

Explanation:

We have been given the discriminant 12

We have to choose the equation which will satisfy the given discriminant.

We will consider all the given equation one by one

First we will take option a which is
`-x^2+8x+2=0`

Discriminant from the equation we will find by the formula

`D=b^2-4ac`

Here, a=-1,b=8 and c=2 on substituting the values we will get

`D=8^2-4(-1)(2)=72`

Hence, option a is incorrect.

Now, we will consider option b which is
`2x^2+6x+3=0`

Here, a=2,b=6 and c=3 on substituting the values we get

`D=(6)^2-4(2)(3)=12`

Hence, option b is correct

Therefore, option b is the required answer.