\r\n" );
document.write( "I taught calculus for 40 years but never heard of \"first principle\". So I\r\n" );
document.write( "assumed you meant the first derivative formula you learn which is the derivative\r\n" );
document.write( "of a power of x. You haven't gotten to the short-cut formulas yet.\r\n" );
document.write( "\r\n" );
document.write( "What you want is what we called \"by using the definition of the derivative\" or\r\n" );
document.write( "\"by the limit of the difference quotient\".\r\n" );
document.write( "\r\n" );
document.write( "
\r\n" );
document.write( "\r\n" );
document.write( "-------------------------------------------------\r\n" );
document.write( "\r\n" );
document.write( "
\r\n" );
document.write( "\r\n" );
document.write( "
\r\n" );
document.write( "\r\n" );
document.write( "
\r\n" );
document.write( "\r\n" );
document.write( "
\r\n" );
document.write( "\r\n" );
document.write( "Multiply top and bottom by LCD = 2x(x+h)\r\n" );
document.write( "\r\n" );
document.write( "
\r\n" );
document.write( "\r\n" );
document.write( "
\r\n" );
document.write( "\r\n" );
document.write( "
\r\n" );
document.write( "\r\n" );
document.write( "Factor h out of the numerator:\r\n" );
document.write( "\r\n" );
document.write( "
\r\n" );
document.write( "\r\n" );
document.write( "Cancel h's\r\n" );
document.write( "\r\n" );
document.write( "
\r\n" );
document.write( "\r\n" );
document.write( "
\r\n" );
document.write( "\r\n" );
document.write( "As h approaches 0 the numerator and denominator approach what we\r\n" );
document.write( "get if we substitute 0 for h, so the limit as h approaches 0 is:\r\n" );
document.write( "\r\n" );
document.write( "
\r\n" );
document.write( "\r\n" );
document.write( "
\r\n" );
document.write( "\r\n" );
document.write( "Edwin
\n" );
document.write( "![\"\"](\"/images/stars/stars-10.gif\")
