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Use the zeros and the labels point to write the quadratic function represented by the graph.

Use the zeros and the labels point to write the quadratic function represented by-example-1
User ToddJCrane
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1 Answer

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zeros: (-1,0) and (2,0)

Use the zeros to write the factors of the function as follow:

zeros: (b,0) and (c,0)


y=a(x-b)(x-c)
\begin{gathered} y=a(x-(-1))(x-2) \\ y=a(x+1)(x-2) \end{gathered}

Use the given oint (1,6) to find the value of a:


\begin{gathered} 6=a(1+1)(1-2) \\ 6=a(2)(-1) \\ 6=-2a \\ (6)/(-2)=a \\ \\ a=-3 \end{gathered}

The function is:


y=-3(x+1)(x-2)

Use FOIL method and distributive property to simplify:


\begin{gathered} y=-3(x*x-2*x+1*x-2*1) \\ y=-3(x^2-2x+x-2) \\ y=-3(x^2-x-2) \\ \\ y=-3x^2+3x+6 \end{gathered}

Then, the function in the graph is y=-3x^+63x+6

Answer: D.

User Jeffhale
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