document.write( "Question 285986: How do I find the stationary points in this equation:\r
\n" );
document.write( "\n" );
document.write( "y=(3x-1)(x-2)^4 \n" );
document.write( "
Algebra.Com's Answer #207391 by solver91311(24713)![]() ![]() You can put this solution on YOUR website! \r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "There are 2 ways to go about this.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "The bull-in-a-china-shop method is to multiply out the five factors and then differentiate the resulting 5th degree polynomial function. Not too difficult really, just a bit of drudgery.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "The other way is to apply the Chain Rule and the Product Rule to find the first derivative of the function. Certainly the more elegant way to do it.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Either way, once you have the first derivative, set it equal to zero. There will be a stationary point at every zero of the first derivative function.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Once you have the first derivative, you will note that it is a rather ugly 4th degree polynomial. But if you look at a graph of the original function (use a graphing application or your graphing calculator, or simply realize that the 5th degree polynomial has a zero at 2 with a multiplicity of 4) you will see that there are only two stationary points, one at 2 and one between 0 and 1, just about 2/3.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "If you take the ugly mess of a 4th degree polynomial function that you get for a first derivative, you will find that you will be successful performing synthetic division three successive times with a divisor of 2. That will leave you with a simple linear equation the solution of which is the remaining stationary point.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Good luck\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "John \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " |