问题标题:
数学:求不定积分|`(2x-x^2)^1/2dx=?
问题描述:
数学:求不定积分|`(2x-x^2)^1/2dx=?
陈胜回答:
令1-x=sinα→dx=-cosαdα原式=-∫cos??αdα=-1/2(∫cos2αdα+∫dα)=[(x-1)√(2x-x??)+arcsin(x-1)]/2+C。
潭天江回答:
1/2arcsinx+1/2[1-(x-1)^2]^1/2+c
汪维清回答:
∫(2x-x^2)^(1/2)dx=∫[1-(x-1)^2]^(1/2)dx令x-1=sint,x=sint+1,dx=costdt则∫(2x-x^2)^(1/2)dx=∫[1-(x-1)^2]^(1/2)dx=∫(cost)^2dt=(1/2)∫(1+cos2t)dt=(1/2)t+(1/4)sin2t+C=(1/2)t+(1/2)sintcost+C=(1/2)arcsin(x-1)+(1/2)(x-1)(2x-x^2)^(1/2)+C
查看更多