题目:
f(x分之1)=1+x平方+x分之x求f(x)的导数f’(x)
解答:
令a=1/xx=1/af(a)=(1/a)/(1+1/a²+1/a)=a/(a²+a+1)f(x)=x/(x²+x+1)所以f"(x)=[1*(x²+x+1)-x*(2x+1)]/(x²+x+1)²=(1-x²)/(x²+x+1)²
时间:2020-12-16 16:49
题目:
f(x分之1)=1+x平方+x分之x求f(x)的导数f’(x)
解答:
令a=1/xx=1/af(a)=(1/a)/(1+1/a²+1/a)=a/(a²+a+1)f(x)=x/(x²+x+1)所以f"(x)=[1*(x²+x+1)-x*(2x+1)]/(x²+x+1)²=(1-x²)/(x²+x+1)²