已知函数f(x)=x²+2/x(x≠0)解不等式f(x)-f(x-1)>2x-1
问题描述:
已知函数f(x)=x²+2/x(x≠0)解不等式f(x)-f(x-1)>2x-1
答
f(x-1)=(x-1)² + 2/(x-1)
f(x)-f(x-1)=x²+2/x - (x-1)² - 2/(x-1)=2x - 1 + 2/x - 2/(x-1)
f(x)-f(x-1)>2x-1 化简即为 2x - 1 + 2/x - 2/(x-1)>2x-1
2/x - 2/(x-1)>0
x(x-1)