document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=100109>Question 100109</A>: <I><SPAN STYLE=\"word-break: break-all;\"> How can I find the vertex while using the quadratic formula? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #72877 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=72877\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> How can I find the vertex while using the quadratic formula?<BR>\n" );
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document.write( "The quadratic formula says there are roots at (-b/2a)+sqrt(b^2-4ac)/(2a)<BR>\n" );
document.write( "and (-b/2a) - sqrt(b^2-4ac)/2a<BR>\n" );
document.write( "So (-b/2a) is the x-value half-way between the two roots.<BR>\n" );
document.write( "It is therefore on the axis of symmetry of the parabola.<BR>\n" );
document.write( "It is therefore the x-value of the vertex of the parabola<BR>\n" );
document.write( "Therefore the vertex is at (-b/2a, f(-b/2a))<BR>\n" );
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document.write( "Cheers,<BR>\n" );
document.write( "Stan H. </SPAN>\n" );
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