解法一：所求体积=2∫2πx√[16-(x-5)²]dx=4π∫x√[16-(x-5)²]dx=4π∫(4sint+5)*4cost*4costdt (令x=4sint+5)=64π∫(4sint+5)cos²tdt=640π∫cos²tdt=320π∫[1+cos(2t)]dt=320π[t+sin(2t)/...