document.write( "Question 691391: Write an equation for the parabola with the vertex (1,3) that passes through (-2,-15).\r
\n" ); document.write( "\n" ); document.write( "I have tried to figure out how to do y=A(x-h)^2, but cannot figure out how to apply it to the problem.\r
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Algebra.Com's Answer #426677 by nerdybill(7384)\"\" \"About 
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Write an equation for the parabola with the vertex (1,3) that passes through (-2,-15)
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\n" ); document.write( "Vertex form of a parabola is
\n" ); document.write( "y = a(x-h)^2 + k
\n" ); document.write( "where
\n" ); document.write( "(h,k) is the vertex
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\n" ); document.write( "Since the problem gives you the vertex we can plug it in:
\n" ); document.write( "y = a(x-1)^2 + 3
\n" ); document.write( "Now, we plug in the given point and solve for a:
\n" ); document.write( "-15 = a(-2-1)^2 + 3
\n" ); document.write( "-15 = a(-3)^2 + 3
\n" ); document.write( "-15 = a(9) + 3
\n" ); document.write( "-18 = a(9)
\n" ); document.write( "-2 = a
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\n" ); document.write( "So, our equation is now:
\n" ); document.write( "y = -2(x-1)^2 + 3\r
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