代换,再分部积分 令t=根号x ,则x=t^2 ,dx=2tdt ∫(2t)(2^t)dt=2∫td(2^t/ln2)=(2/ln2)t(2^t)-(2/ln2)∫2^tdt =(2/ln2)t(2^t)-(2/ln2) (2^t/ln2)+C 带回t=根号x即可
