f(x)=則f(x-1)dx=().
(2x+|x|+1)2dx=().
已知生產(chǎn)某產(chǎn)品x單位(百臺)的邊際成本函數(shù)和邊際收益函數(shù)分別為MC=C′(x)=3+x(萬元/百臺);MR=R′(x)=7-x(萬元/百臺).