另1-x^2=u,则原式:
(1-u)*(u)^0.5=u^0.5-u^1.5
不定积分=1/1.5u^1.5-1/2.5u^2.5
换限:计算还是1,0
积分值=1/1.5-1/2.5=2/3-2/5=4/15