Mattie uses the discriminant to determine the number of zeros the quadratic equation [tex]0 = 3x^2 - 7x + 4[/tex] has. Which best describes the discriminant and the number of zeros?

A. The equation has one zero because the discriminant is 1.
B. The equation has one zero because the discriminant is a perfect square.
C. The equation has two zeros because the discriminant is greater than 0.
D. The equation has no zeros because the discriminant is not a perfect square.



Answer :

To determine the number of zeros (roots) of the quadratic equation [tex]\(0 = 3x^2 - 7x + 4\)[/tex], we need to use the discriminant of the quadratic formula.

The general form of a quadratic equation is [tex]\(ax^2 + bx + c = 0\)[/tex]. For the given equation:

- [tex]\(a = 3\)[/tex]
- [tex]\(b = -7\)[/tex]
- [tex]\(c = 4\)[/tex]

The discriminant ([tex]\(\Delta\)[/tex]) of a quadratic equation [tex]\(ax^2 + bx + c = 0\)[/tex] is calculated using the formula:
[tex]\[ \Delta = b^2 - 4ac \][/tex]

Let's substitute the values [tex]\(a\)[/tex], [tex]\(b\)[/tex], and [tex]\(c\)[/tex] into this formula:

1. Calculate [tex]\(b^2\)[/tex]:
[tex]\[ (-7)^2 = 49 \][/tex]

2. Calculate [tex]\(4ac\)[/tex]:
[tex]\[ 4 \cdot 3 \cdot 4 = 48 \][/tex]

3. Compute the discriminant:
[tex]\[ \Delta = 49 - 48 = 1 \][/tex]

Now that we have the discriminant [tex]\(\Delta = 1\)[/tex], we can determine the number of zeros:

- If the discriminant ([tex]\(\Delta\)[/tex]) is greater than 0, the quadratic equation has two real and distinct zeros.
- If the discriminant ([tex]\(\Delta\)[/tex]) is equal to 0, the quadratic equation has exactly one real zero (a repeated root).
- If the discriminant ([tex]\(\Delta\)[/tex]) is less than 0, the quadratic equation has no real zeros (the roots are complex).

Since our discriminant [tex]\(\Delta = 1\)[/tex] is greater than 0, this means:

- The equation has two real and distinct zeros.

Therefore, the best description of the discriminant and the number of zeros is:
[tex]\[ \text{The equation has two zeros because the discriminant is greater than 0.} \][/tex]