document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=675648>Question 675648</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Find the quadratic function <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=f%28x%29=ax%5E2%2Bbx%2Bc ALIGN=MIDDLE  ALT=\"f%28x%29=ax%5E2%2Bbx%2Bc\"   DISABLED_style= \"max-width:90%; height:auto;\" > for which f(1)=6 , f(-2)=18 , and f(2)=6. I need help with this one. I am having a hard time figuring it out!  </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #419952 by </B><A HREF=/tutors/aboutme.mpl?userid=stanbon><B>stanbon(75887)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=stanbon><IMG SRC=http://www.algebra.com/images/aboutme-small.gif BORDER=0 alt=\"About Me\" VALIGN=MIDDLE></A>&nbsp;<IMG SRC=http://www.algebra.com/images/nopicture.jpg><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=419952\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Find the quadratic function <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=f%28x%29=ax%5E2%2Bbx%2Bc ALIGN=MIDDLE  ALT=\"f%28x%29=ax%5E2%2Bbx%2Bc\"   DISABLED_style= \"max-width:90%; height:auto;\" > for which<BR>\n" );
document.write( "You have 3 points. Substitute into the quadratic form and solve the system:<BR>\n" );
document.write( "---------------------------------- <BR>\n" );
document.write( "f(1)=6 ::: a + b + c = 6<BR>\n" );
document.write( "f(-2)=18::4a -2b + c = 18<BR>\n" );
document.write( "f(2)=6::::4a +2b + c = 6<BR>\n" );
document.write( "-------<BR>\n" );
document.write( "I used a matrix method on a TI-84 to get:<BR>\n" );
document.write( "a = 1<BR>\n" );
document.write( "b = -3<BR>\n" );
document.write( "c = 1<BR>\n" );
document.write( "==========<BR>\n" );
document.write( "Equation:<BR>\n" );
document.write( "y = x^2 -3x + 1<BR>\n" );
document.write( "====================<BR>\n" );
document.write( "Cheers,<BR>\n" );
document.write( "Stan H. </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );