4. a) Marginal profit is P' = 6x+5. Find the accumulated profit (change in profit) when the units x increase from 8 to 12. P = ( 1 (6*+5) 2x = 6X3 X=12 +5x X = 8 = 3x -+5 x/ 12 1x=8 = ) 3 ( 12 ) + 5 ( 12 ) - 3 18) 2 + 5 ( 8)] = 3 ( 144) +60 - 3 ( 64)+ 40 ) ] => 432+60- (192+ 40 ) = 492-232 = 260 b) Find the area under the curve y= -+e"*+ vx and bounded below by the x axis for X Is x $4. Also graph the given curve and shade in the area. Use 3 place accuracy. areas text Ux ) Qx = 3danx - ex + X 3/ 2 14 3/2/4 3 /2 + 2 X = 73/4- 24+ 2 (8) - [ 3. 0+ # + 2 ] = 8.439 4