document.write( "Question 48689: Maximizing profit. The total profit (in dollars) for sales of x rowing machines is given by p(x)= -0.2x^2+300x-200 . What is the profit if 500 are sold? For what value of x will the profit be at a maximum? \n" ); document.write( "
Algebra.Com's Answer #32223 by longjonsilver(2297)![]() ![]() You can put this solution on YOUR website! the differential gives you a turning point on a curve, either a max or a min (or a point of inflexion).\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "p(x)= -0.2x^2+300x-200 \n" ); document.write( "p'(x)= -0.4x+300 where p'(x) is the differential \n" ); document.write( "p'(x)= -0.4x+300 = 0 \n" ); document.write( "0.4x = 300 \n" ); document.write( "x = 300/0.4 \n" ); document.write( "x = 750\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "p''(x) = -0.4 which is NEGATIVE. This is therefore a MAXIMUM point.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "So profit is maximised at x=750\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "jon. \n" ); document.write( " \n" ); document.write( " |