document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=211314>Question 211314</A>This question is from textbook <A HREF=http://www.amazon.com/exec/obidos/ASIN/0395977258/algebrahomeworkh></A><BR>\n" );
document.write( ": <I><SPAN STYLE=\"word-break: break-all;\"> Find (a) the directrix, (b) the focus and (c) the roots of the parabola \r<BR>\n" );
document.write( "\n" );
document.write( "      y=x2-5x+4  </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #159661 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=159661\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Find (a) the directrix, (b) the focus and (c) the roots of the parabola <BR>\n" );
document.write( "y=x^2-5x+4 <BR>\n" );
document.write( "-----------------------------<BR>\n" );
document.write( "Complete the square:<BR>\n" );
document.write( "x^2-5x+? = y-4 +?<BR>\n" );
document.write( "x^2-5x + (5/2)^2 = y - 4 + (5/2)^2<BR>\n" );
document.write( "(x-(5/2))^2 = y + (9/4)<BR>\n" );
document.write( "----------------------------------<BR>\n" );
document.write( "Vertex at (5/2 , -9/4)<BR>\n" );
document.write( "4p = 1<BR>\n" );
document.write( "p = 1/4<BR>\n" );
document.write( "---<BR>\n" );
document.write( "Focus at (5/2, (-9/4)+(1/4)) = (5/2 , -2)<BR>\n" );
document.write( "--------------<BR>\n" );
document.write( "Roots:<BR>\n" );
document.write( "Solve x^2-5x+4 = 0<BR>\n" );
document.write( "Factor:<BR>\n" );
document.write( "(x-4)(x-1) = 0<BR>\n" );
document.write( "x = 4 ; x = 1<BR>\n" );
document.write( "==========================<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=graph%28400%2C300%2C-10%2C10%2C-10%2C10%2Cx%5E2-5x%2B4%29 ALIGN=MIDDLE  ALT=\"graph%28400%2C300%2C-10%2C10%2C-10%2C10%2Cx%5E2-5x%2B4%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "================================================<BR>\n" );
document.write( "Cheers.<BR>\n" );
document.write( "Stan H. </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );