document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=93472>Question 93472</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 the what what and the what? please help me!!!  Find (a)the directrix,<BR>\n" );
document.write( "(b) the focus and (c) the roots of the parabola y = x^2 - 5x + 4 <BR>\n" );
document.write( "(a)_________________<BR>\n" );
document.write( "(b)_________________<BR>\n" );
document.write( "(c)_________________ </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #68059 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=68059\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Find (a)the directrix,<BR>\n" );
document.write( "(b) the focus and (c) the roots of the parabola y = x^2 - 5x + 4 <BR>\n" );
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document.write( "Complete the square on the x terms and keep the equation balanced:<BR>\n" );
document.write( " x^2 - 5x + 4 = y<BR>\n" );
document.write( "x^2 -5x + ? = y-4 + ?<BR>\n" );
document.write( "x^2 + 5x + (5/2)^2 = y - 16/4 + (25/4)<BR>\n" );
document.write( "Factor and simplify to get:<BR>\n" );
document.write( "(x+(5/2))^2 = (y+9/4)<BR>\n" );
document.write( "Note: This follows the form (x-h)^2 = 4P(y-k)\r<BR>\n" );
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document.write( "a) directrix is x = -5/2<BR>\n" );
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document.write( "b) 4P=1; p=1/4<BR>\n" );
document.write( "Vertex is (-5/2 , -9/4)<BR>\n" );
document.write( "Focus is (-5/2 , -9/4 + 1/4) = (-5/2 , -2)<BR>\n" );
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document.write( "c) Roots:<BR>\n" );
document.write( "y = x^2 - 5x + 4 <BR>\n" );
document.write( "Let y=0 and solve for x:<BR>\n" );
document.write( "x^2-5x+4 = 0<BR>\n" );
document.write( "(x-4)(x-1) = 0<BR>\n" );
document.write( "x=4 or x=1<BR>\n" );
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document.write( "Cheers,<BR>\n" );
document.write( "Stan H.\r<BR>\n" );
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document.write( " </SPAN>\n" );
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