In the previous process, replace x 1 with x2, and you will get that the solution of the same equation is the same.
Where is the maximum value of quadratic function? "
Obviously, your foundation is not very good. Everything you ask is basic. You can understand them by reading more textbooks. It is more important to understand the train of thought of this topic. This topic is actually very simple, knowing the slope of a straight line. You only need xm-xn or ym-yn, and it is very mechanical to solve these things. Children should eat more snacks, hehe.