document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=320392>Question 320392</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Convert the equation y(x)= -2(x-k)^2 + 4 into the standard form.  Assume k is a constant whose value you do not know.\r<BR>\n" );
document.write( "\n" );
document.write( "I keep ending up with an extra k that doesn't fit into the standard equation:<BR>\n" );
document.write( "y(x)= -2(x-k)^2 + 4<BR>\n" );
document.write( "= -2(x-k)(x-k)+4<BR>\n" );
document.write( "= -2(x^2 -xk -xk +k)+4<BR>\n" );
document.write( "= -2(x^2-2xk +k)+4<BR>\n" );
document.write( "= -2x^2 +4xk +k +4  not quite standard form! </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #229443 by </B><A HREF=/tutors/aboutme.mpl?userid=Fombitz><B>Fombitz(32388)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Fombitz><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=Fombitz><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=229443\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Your derivation is correct except you made a small mistake by not distributing correctly,<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=y%28x%29=+-2%28x%5E2-2xk+%2Bk%29%2B4 ALIGN=MIDDLE  ALT=\"y%28x%29=+-2%28x%5E2-2xk+%2Bk%29%2B4\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=y%28x%29=+-2x%5E2+%2B4xk-2k+%2B4 ALIGN=MIDDLE  ALT=\"y%28x%29=+-2x%5E2+%2B4xk-2k+%2B4\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=y%28x%29=-2x%5E2%2B4kx%2B%284-2k%29 ALIGN=MIDDLE  ALT=\"y%28x%29=-2x%5E2%2B4kx%2B%284-2k%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "Comparing to the general equation <BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=y%28x%29=ax%5E2%2Bbx%2Bc ALIGN=MIDDLE  ALT=\"y%28x%29=ax%5E2%2Bbx%2Bc\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=a=-2 ALIGN=MIDDLE  ALT=\"a=-2\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=b=4k ALIGN=MIDDLE  ALT=\"b=4k\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=c=4-2k ALIGN=MIDDLE  ALT=\"c=4-2k\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "Since <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=k ALIGN=MIDDLE  ALT=\"k\"   DISABLED_style= \"max-width:90%; height:auto;\" > is a constant, <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=4-2k ALIGN=MIDDLE  ALT=\"4-2k\"   DISABLED_style= \"max-width:90%; height:auto;\" > is also just a constant.<BR>\n" );
document.write( " </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );