达布上和与下和 上积分(外包) 达布上和的极限 f(x)tx=im∑M (R)f(x)dx=hmn∑f(·Rmm积分 |→>0 下积分(内填)达布下和的极限 f(x)dx m△ 7|-→>0•达布上和与下和 • Riemann积分 i n i i T b a R f x dx = f x = → 1 || || 0 ( ) ( ) lim ( ) xi-1 xi i n i i T b a f x dx = m x = → 1 || || 0 ( ) lim 下积分(内填) 达布下和的极限 xi-1 xi i n i i T b a f x dx = M x = → 1 || || 0 ( ) lim 上积分(外包) 达布上和的极限