The form of basic inequality is: a+b >; =2√ab (condition of equal sign: if and only if a=b), so when using basic inequality, it is mainly to solve the maximum problem! When it comes to the form of a+b or the addition of two numbers, if the topic requires a minimum, use a+b >. =2√ab (if and only if a=b), when it comes to √ab or the product of two numbers, the topic requires a+b > to find the maximum value; =2√ab. But the basic inequality is sometimes generalized, such as (1) A 3+B 3+C 3 > =3abc (if and only if a=b=c), (2) (a1+a2+a3+...)/n >; =(a 1a2a3 ...) to power n, (the condition of the equal sign is if and only if a 1=a2=a3= ...), (3) a+1/a > =2 (if and only if a= 1/a) and a is a positive real number, (4) a+1/a.
And A and B have the same symbol (6) A2+B2+C2 >; =ab+bc+ac (equal sign condition: if and only if a=b=c)
You can ask the teacher questions about basic inequalities. It's not difficult to say it's difficult, but it's not easy to say it. You should study hard, because it is very useful (when solving big problems)! When you encounter a problem, simply use the derivative to find monotonicity and compare it with the best value!