用降次公式:[cos(wt)]^2=(cos2wt+1)/2
原式=∫[(cos2wt+1)/2]dt=(1/2)∫(cos2wt+1)dt=(1/4w)∫(cos2wt+1)d(2wt)=(1/4w)(2wt+sin2wt)在(0,π/(3w))上=√3/8w+π/6w
说明:√是根号
用降次公式:[cos(wt)]^2=(cos2wt+1)/2
原式=∫[(cos2wt+1)/2]dt=(1/2)∫(cos2wt+1)dt=(1/4w)∫(cos2wt+1)d(2wt)=(1/4w)(2wt+sin2wt)在(0,π/(3w))上=√3/8w+π/6w
说明:√是根号