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Question 5 of 10

Find the discriminant and the number of real roots for this equation.
[tex]\[ x^2 + 3x + 8 = 0 \][/tex]

A. [tex]\(-23\)[/tex]; one real root
B. [tex]\(32\)[/tex]; two real roots
C. [tex]\(-23\)[/tex]; no real roots
D. [tex]\(32\)[/tex]; one real root



Answer :

To find the discriminant and number of real roots for the quadratic equation [tex]\(x^2 + 3x + 8 = 0\)[/tex], follow the steps below:

### Step 1: Identify the Coefficients
In the quadratic equation of the form [tex]\(ax^2 + bx + c = 0\)[/tex]:

- [tex]\(a\)[/tex] is the coefficient of [tex]\(x^2\)[/tex]
- [tex]\(b\)[/tex] is the coefficient of [tex]\(x\)[/tex]
- [tex]\(c\)[/tex] is the constant term

For the given equation [tex]\(x^2 + 3x + 8 = 0\)[/tex]:
- [tex]\(a = 1\)[/tex]
- [tex]\(b = 3\)[/tex]
- [tex]\(c = 8\)[/tex]

### Step 2: Calculate the Discriminant
The discriminant [tex]\(\Delta\)[/tex] of a quadratic equation [tex]\(ax^2 + bx + c = 0\)[/tex] is given by the formula:
[tex]$\Delta = b^2 - 4ac$[/tex]

Substitute the values of [tex]\(a\)[/tex], [tex]\(b\)[/tex], and [tex]\(c\)[/tex]:
[tex]$\Delta = 3^2 - 4(1)(8)$[/tex]
[tex]$\Delta = 9 - 32$[/tex]
[tex]$\Delta = -23$[/tex]

### Step 3: Interpret the Discriminant
The value of the discriminant determines the number and type of roots of the quadratic equation:
- If [tex]\(\Delta > 0\)[/tex], there are two distinct real roots.
- If [tex]\(\Delta = 0\)[/tex], there is one real root (a repeated root).
- If [tex]\(\Delta < 0\)[/tex], there are no real roots; the roots are complex.

Here, [tex]\(\Delta = -23\)[/tex], which is less than 0. This means the quadratic equation [tex]\(x^2 + 3x + 8 = 0\)[/tex] has no real roots.

### Conclusion
The discriminant of the given quadratic equation is [tex]\(\Delta = -23\)[/tex], and it has no real roots.

Thus, the correct answer is:

C. [tex]\(-23\)[/tex] ; no real roots