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Can I get help writing an equation in standard form for the parabola

Can I get help writing an equation in standard form for the parabola-example-1
User Zooglash
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1 Answer

13 votes
13 votes

To solve this problem, first, we use the following form of the equation of a vertical parabola:


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

where (h,k) are the coordinates of the vertex.

Using the above form and the graph, we get:


y=a(x+4)^2+2.

Now, to determine the value of a, we consider the point (-2,0) on the parabola:


0=a(-2+4)^2+2.

Solving for a, we get:


\begin{gathered} -2=a2^2, \\ -(2)/(4)=a, \\ a=-(1)/(2). \end{gathered}

Therefore:


y=-(1)/(2)(x+4)^2+2.

Finally, we take the above equation to its standard form:


\begin{gathered} y=-(1)/(2)(x^2+8x+16)+2, \\ y=-(1)/(2)x^2-4x-8+2, \\ y=-(1)/(2)x^2-4x-6. \end{gathered}

Answer:


y=-(1)/(2)x^2-4x-6.

User Tim Peters
by
2.7k points
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