解:(10)题,设x^(1/4)=t,则dx=4t^3dt, 原式=4∫t^2dt/(1+t)=4∫[t-1+1/(1+t)]dt=2t^2-4t+4ln(1+t)+C=2x^(1/2)-4x^(1/4)+4ln[1+x^(1/4)]+C。 (12)题,设t=[(x-1)/(x+1)]^(1/3),则dx=6t^2dt/(1-t^3)^2, 原式=(3/2)∫dt/t^2=-(3/2)/t+C=(-3/2)[(x+1)/(x-1)]^(1/3)+C。 供参考。