1、令[根号(x+1)]=t,则x=t^2-1,dx=2tdt,所以原式=∫(t^2-1)t×2tdt =∫(2t^4-2t^2)dt =(2/5)t^5-(2/3)t^3+C =(2/5)[(x+1)^(5/2)]-(2/3)[(x+1)^(3/2)]+C 2、∫lnxdx =xlnx-∫xd(lnx) =xlnx-x+C 所以, ∫lnxdx =(xlnx-x+C)| =1 3、令F(x,y,z)=(x^2/a^2+y^2/b^2+z^2/c^2-1) 则Fx=2x/a^2,Fy=2y/b^2,Fz=2z/c^2 (上面的F后面的x、y、z为下标)所以,偏导数のz/のx=﹣Fx/Fz=﹣[(c^2)x]/[(a^2)z] のz/のy=﹣Fy/Fz=﹣[(c^2)y]/[(b^2)z] (の表示偏导数符号)