document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1120312>Question 1120312</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Find a quadratic model for the set of values.\r<BR>\n" );
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document.write( "   x -2, 0, 4\r<BR>\n" );
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document.write( "f(x) 4, 6, -38  </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #735969 by </B><A HREF=/tutors/aboutme.mpl?userid=ankor@dixie-net.com><B>ankor@dixie-net.com(22740)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=ankor@dixie-net.com><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/cgi-bin/show-face.mpl?user=ankor@dixie-net.com><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=735969\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Find a quadratic model for the set of values. <BR>\n" );
document.write( "x -2, 0, 4 <BR>\n" );
document.write( "f(x) 4, 6, -38 <BR>\n" );
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document.write( " x | y<BR>\n" );
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document.write( "-2 | 4<BR>\n" );
document.write( " 0 | 6<BR>\n" );
document.write( " 4 |-38<BR>\n" );
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document.write( "Use the form ax^2 + bx + c = y<BR>\n" );
document.write( "When x=0, y=6, therefore c = 6<BR>\n" );
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document.write( "when x=-2; y=4<BR>\n" );
document.write( "(-2^2)a + - 2b + 6 = 4<BR>\n" );
document.write( "4a - 2b = 4 - 6<BR>\n" );
document.write( "4a - 2b = -2<BR>\n" );
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document.write( "when x=4; y=-38<BR>\n" );
document.write( "16a + 4b + 6 = -38<BR>\n" );
document.write( "16a + 4b = -38 - 6<BR>\n" );
document.write( "16a + 4b = -44<BR>\n" );
document.write( "simplify, divide by 2<BR>\n" );
document.write( "8a + 2b = -22<BR>\n" );
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document.write( "4a - 2b = -2<BR>\n" );
document.write( "8a + 2b = -22<BR>\n" );
document.write( "---------------addition eliminates b, find a<BR>\n" );
document.write( "12a + 0 = -24<BR>\n" );
document.write( "a = -24/12<BR>\n" );
document.write( "a = -2<BR>\n" );
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document.write( "Find b<BR>\n" );
document.write( "4(-2) - 2b = -2<BR>\n" );
document.write( "-8 - 2b = -2<BR>\n" );
document.write( "-2b = -2 + 8<BR>\n" );
document.write( "-2b = 6<BR>\n" );
document.write( "b = 6/-2<BR>\n" );
document.write( "b = -3<BR>\n" );
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document.write( "The equation f(x) = -2x^2 - 3x + 6, is the quadratic model<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+graph%28+300%2C+200%2C+-6%2C+5%2C+-40%2C+20%2C+-2x%5E2+-+3x+%2B+6%2C+-38%29+ ALIGN=MIDDLE  ALT=\"+graph%28+300%2C+200%2C+-6%2C+5%2C+-40%2C+20%2C+-2x%5E2+-+3x+%2B+6%2C+-38%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "green line = -38<BR>\n" );
document.write( " </SPAN>\n" );
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