Questions: Solving Quadratic Equations by
Select the correct answer.
Solve the following equation by completing the square.
1/4 x^2 + x + 1/4 = 0
A. x = -2 + sqrt(3) or x = -2 - sqrt(3)
B. x = -2 + sqrt(3) or x = 2 - sqrt(3)
C. x = 1 or x = -5
D. x = 2 + sqrt(3) or x = 2 - sqrt(3)
Transcript text: Solving Quadratic Equations by
Select the correct answer.
Solve the following equation by completing the square.
\[
\frac{1}{4} x^{2}+x+\frac{1}{4}=0
\]
A. $x=-2+\sqrt{3}$ or $x=-2-\sqrt{3}$
B. $x=-2+\sqrt{3}$ or $x=2-\sqrt{3}$
C. $x=1$ or $x=-5$
D. $x=2+\sqrt{3}$ or $x=2-\sqrt{3}$
Solution
Solution Steps
Step 1: Clear the Fraction
We start with the equation
\[
\frac{1}{4} x^{2} + x + \frac{1}{4} = 0
\]
To eliminate the fraction, we multiply the entire equation by 4:
\[
x^{2} + 4x + 1 = 0
\]
Step 2: Move the Constant Term
Next, we move the constant term to the right side of the equation:
\[
x^{2} + 4x = -1
\]
Step 3: Complete the Square
To complete the square, we add \(\left(\frac{b}{2}\right)^{2}\) to both sides, where \(b = 4\):
\[
x^{2} + 4x + 4 = 3
\]
This simplifies to:
\[
(x + 2)^{2} = 3
\]
Step 4: Solve for \(x\)
Taking the square root of both sides gives us:
\[
x + 2 = \pm \sqrt{3}
\]
Thus, we can solve for \(x\):
\[
x = -2 + \sqrt{3} \quad \text{or} \quad x = -2 - \sqrt{3}
\]