求原函数。
1个回答
展开全部
原式=(1/3)∫arctanxd(x³)
=(1/3)[x³arctanx-∫x³d(arctanx)]
=(1/3)x³arctanx-(1/3)∫[x³/(1+x²)]dx
=(1/3)x³arctanx-(1/6)∫[x²/(1+x²)]d(x²)
=(1/3)x³arctanx-(1/6)∫[(x²+1-1)/(1+x²)]d(x²)
=(1/3)x³arctanx-(1/6)∫d(x²)+(1/6)∫[1/(1+x²)]d(x²+1)
=(1/3)x³arctanx-(1/6)x²+(1/6)ln(1+x²)+C
=(1/3)[x³arctanx-∫x³d(arctanx)]
=(1/3)x³arctanx-(1/3)∫[x³/(1+x²)]dx
=(1/3)x³arctanx-(1/6)∫[x²/(1+x²)]d(x²)
=(1/3)x³arctanx-(1/6)∫[(x²+1-1)/(1+x²)]d(x²)
=(1/3)x³arctanx-(1/6)∫d(x²)+(1/6)∫[1/(1+x²)]d(x²+1)
=(1/3)x³arctanx-(1/6)x²+(1/6)ln(1+x²)+C
推荐律师服务:
若未解决您的问题,请您详细描述您的问题,通过百度律临进行免费专业咨询