Answered

Get reliable answers to your questions at Westonci.ca, where our knowledgeable community is always ready to help. Join our platform to connect with experts ready to provide precise answers to your questions in different areas. Get detailed and accurate answers to your questions from a dedicated community of experts on our Q&A platform.

Select the two values of [tex]$x$[/tex] that are roots of this equation:

[tex]\[ x^2 - 5x + 2 = 0 \][/tex]

A. [tex]$x=\frac{5+\sqrt{17}}{2}$[/tex]

B. [tex]$x=\frac{5-\sqrt{17}}{2}$[/tex]

C. [tex][tex]$x=\frac{5+\sqrt{33}}{2}$[/tex][/tex]

D. [tex]$x=\frac{5-\sqrt{33}}{2}$[/tex]


Sagot :

To find the roots of the quadratic equation [tex]\( x^2 - 5x + 2 = 0 \)[/tex], we can use the quadratic formula, which states:

[tex]\[ x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a} \][/tex]

For the given equation [tex]\( x^2 - 5x + 2 = 0 \)[/tex], we identify the coefficients:
- [tex]\( a = 1 \)[/tex]
- [tex]\( b = -5 \)[/tex]
- [tex]\( c = 2 \)[/tex]

Step 1: Compute the discriminant [tex]\(\Delta\)[/tex].
[tex]\[ \Delta = b^2 - 4ac = (-5)^2 - 4 \cdot 1 \cdot 2 = 25 - 8 = 17 \][/tex]

Step 2: Calculate the roots using the quadratic formula.
[tex]\[ x_{1,2} = \frac{-b \pm \sqrt{\Delta}}{2a} \][/tex]

Since [tex]\( b = -5 \)[/tex] and [tex]\( \Delta = 17 \)[/tex]:
[tex]\[ x = \frac{5 \pm \sqrt{17}}{2} \][/tex]

Thus, the roots are:
[tex]\[ x_1 = \frac{5 + \sqrt{17}}{2}, \quad x_2 = \frac{5 - \sqrt{17}}{2} \][/tex]

Step 3: Identify the correct options given in the problem.
The equations corresponding to the given roots and answers are:
- Option A: [tex]\( x = \frac{5 + \sqrt{17}}{2} \)[/tex]
- Option B: [tex]\( x = \frac{5 - \sqrt{17}}{2} \)[/tex]
- Option C: [tex]\( x = \frac{5 + \sqrt{33}}{2} \)[/tex]
- Option D: [tex]\( x = \frac{5 - \sqrt{33}}{2} \)[/tex]

From the calculations:
The correct roots are:
[tex]\[ x_1 = \frac{5 + \sqrt{17}}{2}, \quad x_2 = \frac{5 - \sqrt{17}}{2} \][/tex]
Matching these with the given options, we identify the correct options as:
- Option A: [tex]\( x = \frac{5 + \sqrt{17}}{2} \)[/tex]
- Option B: [tex]\( x = \frac{5 - \sqrt{17}}{2} \)[/tex]

Therefore, the correct selections for the roots are:
[tex]\[ \boxed{A \text{ and } B} \][/tex]