Process: Take the derivative first, get F (x)' = 2x-1/(x+1/2), record 2x+ 1=y, so f(x)'=y-2/y- 1, and then 0) Then analyze, you should know, right? It's simple, you still have to work hard. I haven't touched math for so many years, but I can work it out soon. Let me tell you some ideas. Encounter such a problem, first ask for guidance. The derivative is invisible at a glance, which is very troublesome. What should you do? Then you have to simplify it and get an easy-to-understand equation, such as the general fraction of denominator and numerator, and remove the fraction in denominator. Then the denominator is a polynomial, which is better to be simple, so consider substitution.