1.5 x3 f(x)= -1 fx)≈48999 0.5 e g10 1.5 S.() 左矩形 梯形 右矩形 4.4429 4.8669 5.2908 5 4.6804 4.8924 5.1044 4.8139 4.8987 4.9835 4.8572 4.8996 4.9420 1010 0 1 2 3 4 5 6 7 8 9 10 0 0.51 1.5 0 1 2 3 4 5 6 7 8 9 1 0 0 0.51 1.5 0 1 2 3 4 5 6 7 8 9 1 0 0 0.51 1.5 ( ) 4.8999 50 f x dx S f x f x h nj n j j 1 1 [ ( ) ( )] 21 1 ( ) 3 x e x f x左矩形 梯形 右矩形 4.4429 4.8669 5.2908 4.6804 4.8924 5.1044 4.8139 4.8987 4.9835 4.8572 4.8996 4.9420