document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=198110>Question 198110</A>: <I><SPAN STYLE=\"word-break: break-all;\"> use the definition of derivative to f'(x) when f(x)=x^2-5x+1<BR>\n" );
document.write( "not getting it </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #148579 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=148579\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> use the definition of derivative to f'(x) when f(x)=x^2-5x+1<BR>\n" );
document.write( "--------<BR>\n" );
document.write( "You need to find \"the limit of [f(x+h)-f(x)]/h as h goes to zero\"<BR>\n" );
document.write( "----------------<BR>\n" );
document.write( "f(x+h) = (x+h)^2 - 5(x+h) + 1<BR>\n" );
document.write( "= x^2 + 2hx + h^2 - 5x -5h +1<BR>\n" );
document.write( "-----------------------------------------<BR>\n" );
document.write( "f(x) = x^2 -5x +1<BR>\n" );
document.write( "-----------------------------------------<BR>\n" );
document.write( "So f(x+h) - f(x) = 2hx + h^2 -5h<BR>\n" );
document.write( "--------------<BR>\n" );
document.write( "Then, dividing by h, you get [f(x+h)-f(x)]/h = 2x + h -5<BR>\n" );
document.write( "---------------------<BR>\n" );
document.write( "Now take the limit as h goes to zero and you get:<BR>\n" );
document.write( "f'(x) = 2x - 5<BR>\n" );
document.write( "=======================<BR>\n" );
document.write( "Hope that helps.<BR>\n" );
document.write( "=======================<BR>\n" );
document.write( "Cheers,<BR>\n" );
document.write( "Stan H. </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );