=f(1)-f(-3)
=pi (9/4 *1 - 3/2 * 1^2 +1^3/3 -1^5/20) - pi (9/4 * (-3) - 3/2 *(-3)^2 +1/3 *(-3)^3 -(-3)^5/20)
=pi (9/4 - 2/3 +1/3 -1/20) - pi(-27/4 -27/2 -9 +243/20)
=pi (135 -40 +20 -3)/60 - pi(-135 -270 -180 + 243)/20
=pi * 112/60 - pi 18/20
=pi * (112 - 18*3)/60=pi * 58/60 =pi 29/30
凑不出你哪个答案,你确认你哪个答案对么?