document.write( "Question 1176694: Vertex (1,3); passing through (2,6) \n" ); document.write( "
Algebra.Com's Answer #803907 by math_tutor2020(3817)\"\" \"About 
You can put this solution on YOUR website!

\n" ); document.write( "Recall that
\n" ); document.write( "\"y+=+a%28x-h%29%5E2+%2B+k\"
\n" ); document.write( "represents the generalized vertex form.
\n" ); document.write( "a = leading coefficient
\n" ); document.write( "h = x coordinate of vertex
\n" ); document.write( "k = y coordinate of vertex\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Since the vertex given to us is (1,3), this means (h,k) = (1,3)
\n" ); document.write( "In other words,
\n" ); document.write( "h = 1
\n" ); document.write( "k = 3\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "We're also told the parabola passes through (x,y) = (2,6)
\n" ); document.write( "x = 2
\n" ); document.write( "y = 6\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "We have these four items of info
\n" ); document.write( "h = 1
\n" ); document.write( "k = 3
\n" ); document.write( "x = 2
\n" ); document.write( "y = 6\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Plug those four items into the first equation mentioned and isolate 'a'.
\n" ); document.write( "\"y+=+a%28x-h%29%5E2+%2B+k\"\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"6+=+a%282-1%29%5E2+%2B+3\"\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"6+=+a%281%29%5E2+%2B+3\"\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"6+=+a+%2B+3\"\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"6-3+=+a\"\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"3+=+a\"\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"a+=+3\"
\n" ); document.write( "The leading coefficient is positive, so the parabola opens upward.\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "We have
\n" ); document.write( "\"y+=+a%28x-h%29%5E2+%2B+k\"
\n" ); document.write( "turn into
\n" ); document.write( "\"y+=+3%28x-1%29%5E2+%2B+3\"
\n" ); document.write( "after plugging in a = 3, h = 1, k = 3\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "We could expand things out and combine like terms like so
\n" ); document.write( "\"y+=+3%28x-1%29%5E2+%2B+3\"\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"y+=+3%28x%5E2-2x%2B1%29+%2B+3\" FOIL rule\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"y+=+3x%5E2-6x%2B3+%2B+3\" Distribute\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"y+=+3x%5E2-6x%2B9\" Combine like terms\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "The vertex form \"y+=+3%28x-1%29%5E2+%2B+3\" expands and simplifies to the standard form \"y+=+3x%5E2-6x%2B9\"\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Graph:
\n" ); document.write( "\"+graph%28+500%2C+500%2C+-10%2C+10%2C+-10%2C+10%2C+0%2C3%28x-1%29%5E2+%2B+3%29+\"
\n" ); document.write( "note the vertex is the lowest point at (1,3)
\n" ); document.write( "
\n" ); document.write( "
\n" );