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What is the standard form of the quadratic function that has a vertex at (4, 5) and goes through the point (5, 6)?

What is the standard form of the quadratic function that has a vertex at (4, 5) and-example-1
User Moris Kramer
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2 Answers

17 votes
17 votes

the standard form of the quadratic function that meets the given conditions is:


\[ y = x^2 - 8x + 21 \]

Therefore, the answer is option B.

To find the standard form of the quadratic function
\(y = ax^2 + bx + c\) that has a vertex at
\((h, k) = (4, 5)\) and passes through the point
\((x, y) = (5, 6)\), we can use the vertex form of a quadratic function and then convert it to standard form. The vertex form of a quadratic function is:


\[ y = a(x - h)^2 + k \]

Given the vertex
\((h, k) = (4, 5)\), we have:


\[ y = a(x - 4)^2 + 5 \]

Now we need to determine the value of \(a\) using the point \((5, 6)\):


\[ 6 = a(5 - 4)^2 + 5 \]


\[ 6 = a(1)^2 + 5 \]


\[ a = 6 - 5 \]


\[ a = 1 \]

So the equation in vertex form is:


\[ y = (x - 4)^2 + 5 \]

To convert this to standard form, we expand the squared term:


\[ y = (x^2 - 8x + 16) + 5 \]


\[ y = x^2 - 8x + 21 \]

Thus, the standard form of the quadratic function that meets the given conditions is:


\[ y = x^2 - 8x + 21 \]

Therefore, the answer is option B.

User David Jesus
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3.0k points
18 votes
18 votes

The vertex form of the equation of a quadratic function is given to be:


y=a(x-h)^2+k

where (h, k) is the vertex.

From the question, we have the following parameters:


\begin{gathered} (h,k)=(4,5) \\ (x,y)=(5,6) \end{gathered}

Therefore, the equation will be in the form:


y=a(x-4)^2+5

At the point (5, 6), we can get the value of a to be:


\begin{gathered} 6=a(5-4)^2+5 \\ a=1 \end{gathered}

Therefore, we have the vertex form to be:


y=(x-4)^2+5

Expanding, we have the equation to be:


\begin{gathered} y=x^2-8x+16+5 \\ y=x^2-8x+21 \end{gathered}

OPTION B is correct.

User John Judd
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2.2k points