document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=316873>Question 316873</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Please help me with this question.  Write the quadratic function in the form<BR>\n" );
document.write( " y=a(x-h) square + k and identify the vertex.\r<BR>\n" );
document.write( "\n" );
document.write( "y= x square - 10x + 18  </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #226845 by </B><A HREF=/tutors/aboutme.mpl?userid=tinbar><B>tinbar(133)</B></A><img src=\"/images/stars/stars-09.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=tinbar><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=226845\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> firstly, you should know that the form y =a(x-h)+k directly tells us the vertex (h, k). Also, k is the optimal value, either a min or max depending on 'a' being + or -. <BR>\n" );
document.write( "y = x^2-10x+18<BR>\n" );
document.write( "y = {x^2-10x} + 18 <- first seperate the constant at the end from the terms that depend on x<BR>\n" );
document.write( "next we have to turn {x^2-10x} into {x-?}^2<BR>\n" );
document.write( "y = {x-5}^2 - 25. we need - 25 becuase {x-5}^2 expanded becomes x^2-10x+25, note that the +25 is an extra value produced when we completed the square. therefore we have to take it away with - 25 resulting in just the first two terms; x^2-10x, which is what we want.\r<BR>\n" );
document.write( "\n" );
document.write( "don forget to add the original 18 constant.<BR>\n" );
document.write( "y={x-5}^2 -25 +18<BR>\n" );
document.write( "y = {x-5}^2 - 7 </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );