如图
(1)∫[1/(x㏑²x)]dx=∫(1/㏑²x)d(㏑x)=-(1/㏑x)+C(2)∫[x/(1+x^4)]dx=(1/2)∫[1/(1+(x²)²)]d(x²)=(1/2)arctan(x²)+C。
