Questions: Find all the zeros of the quadratic function.
y=x^2-11x-26
Transcript text: Find all the zeros of the quadratic function.
\[
y=x^{2}-11 x-26
\]
Solution
Solution Steps
To find the zeros of the quadratic function \( y = x^2 - 11x - 26 \), we need to solve the equation \( x^2 - 11x - 26 = 0 \). This can be done using the quadratic formula, which is given by \( x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a} \), where \( a \), \( b \), and \( c \) are the coefficients of the quadratic equation \( ax^2 + bx + c = 0 \).
Solution Approach
Identify the coefficients \( a = 1 \), \( b = -11 \), and \( c = -26 \).
Use the quadratic formula to calculate the roots of the equation.
Compute the discriminant \( b^2 - 4ac \) to determine the nature of the roots.
Calculate the two possible values for \( x \) using the quadratic formula.
Step 1: Identify the Coefficients
The given quadratic function is \( y = x^2 - 11x - 26 \). The coefficients are:
\( a = 1 \)
\( b = -11 \)
\( c = -26 \)
Step 2: Calculate the Discriminant
The discriminant of a quadratic equation \( ax^2 + bx + c = 0 \) is given by \( \Delta = b^2 - 4ac \).
\[
\Delta = (-11)^2 - 4 \times 1 \times (-26) = 121 + 104 = 225
\]
Step 3: Determine the Roots Using the Quadratic Formula
The roots of the quadratic equation are given by:
\[
x = \frac{-b \pm \sqrt{\Delta}}{2a}
\]
Substituting the values:
\[
x_1 = \frac{-(-11) + \sqrt{225}}{2 \times 1} = \frac{11 + 15}{2} = \frac{26}{2} = 13.0
\]
\[
x_2 = \frac{-(-11) - \sqrt{225}}{2 \times 1} = \frac{11 - 15}{2} = \frac{-4}{2} = -2.0
\]