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Write a quadratic equation to match the relationship given in the table

Write a quadratic equation to match the relationship given in the table-example-1
User Dspfnder
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1 Answer

7 votes

In order to find the quadratic equation, let's use the standard form of a quadratic equation:


y=ax^2+bx+c

Using the point (0, 2) from the table, we have:


\begin{gathered} 2=a\cdot0^2+b\cdot0+c \\ c=2 \end{gathered}

Now, using the points (-1, -2) and (1, 22):


\begin{gathered} -2=a(-1)^2+b(-1)+2 \\ a-b=-4 \\ 22=a(1)^2+b(1)+2 \\ a+b=20 \end{gathered}

Adding both equations, we can solve for a:


\begin{gathered} a-b+(a+b)=-4+(20) \\ 2a=16 \\ a=8 \\ a+b=20 \\ 8+b=20 \\ b=12 \end{gathered}

Therefore the equation is y = 8x² + 12x + 2

User Najih Km
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