document.write( "Question 729712: I need to find the equation of the quadratic function. I need to express my answer in the form P(x)=ax^+bx+c. The vertex is (-1,-4); through (5,104). I have no idea how to do this. Please help! Thanks! \n" ); document.write( "
Algebra.Com's Answer #446205 by nerdybill(7384)\"\" \"About 
You can put this solution on YOUR website!
I need to express my answer in the form P(x)=ax^+bx+c. The vertex is (-1,-4); through (5,104).
\n" ); document.write( ".
\n" ); document.write( "\"Vertex form\" of quadratic:
\n" ); document.write( "y = a(x-h)^2 + k
\n" ); document.write( "where
\n" ); document.write( "(h,k) is the vertex
\n" ); document.write( ".
\n" ); document.write( "since the problem gives you the vertex (-1,-4) and one point (5,104) plug it in to the vertex form and solve for 'a':
\n" ); document.write( "y = a(x-h)^2 + k
\n" ); document.write( "104 = a(5-(-1))^2 + (-4)
\n" ); document.write( "104 = a(5+1)^2 - 4
\n" ); document.write( "104 = a(6)^2 - 4
\n" ); document.write( "104 = a(36) - 4
\n" ); document.write( "108 = a(36)
\n" ); document.write( "3 = a
\n" ); document.write( ".
\n" ); document.write( "Now, our vertex form is:
\n" ); document.write( "y = a(x-h)^2 + k
\n" ); document.write( "y = 3(x-(-1))^2 + (-4)
\n" ); document.write( "y = 3(x+1)^2 - 4
\n" ); document.write( ".
\n" ); document.write( "we now convert the above to the correct form:
\n" ); document.write( "y = 3(x+1)^2 - 4
\n" ); document.write( "y = 3(x+1)(x+1) - 4
\n" ); document.write( "y = 3(x^2+2x+1) - 4
\n" ); document.write( "y = 3x^2+6x+3 - 4
\n" ); document.write( "y = 3x^2+6x-1
\n" ); document.write( "so,
\n" ); document.write( "P(x)=3x^2+6x-1 (answer)\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( " \n" ); document.write( "
\n" );