Questions: Given (f(x)=-3 x^2-18 x-22), write the function in vertex form. Write your answer in function notation by starting your answer with (f(x)=)
Transcript text: Given $f(x)=-3 x^{2}-18 x-22$, write the function in vertex form. Write your answer in function notation by starting your answer with $f(x)=$
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Solution
Solution Steps
To convert the quadratic function \( f(x) = -3x^2 - 18x - 22 \) into vertex form, we need to complete the square. The vertex form of a quadratic function is given by \( f(x) = a(x-h)^2 + k \), where \((h, k)\) is the vertex of the parabola.
Solution Approach
Factor out the coefficient of \( x^2 \) from the first two terms.
Complete the square inside the parentheses.
Adjust the constant term outside the parentheses to maintain equality.
Write the function in the form \( f(x) = a(x-h)^2 + k \).
Step 1: Identify the Function
We start with the quadratic function given by
\[
f(x) = -3x^2 - 18x - 22.
\]
Step 2: Factor Out the Coefficient
We factor out the coefficient of \( x^2 \) from the first two terms:
\[
f(x) = -3\left(x^2 + 6x\right) - 22.
\]
Step 3: Complete the Square
To complete the square, we take the coefficient of \( x \) (which is 6), halve it to get 3, and then square it to obtain 9. We add and subtract this value inside the parentheses:
\[
f(x) = -3\left(x^2 + 6x + 9 - 9\right) - 22.
\]
This simplifies to:
\[
f(x) = -3\left((x + 3)^2 - 9\right) - 22.
\]