If you can use simplified topics, it is naturally the best. . . The marking principle of college entrance examination papers is to change from the back to the front. If the answer is correct, give full marks; If it is wrong, look at the process. Of course, almost every high school teacher and the person who corrects the paper knows the polar coordinate method. But ... . General college entrance examination questions can avoid using polar coordinates, at least as difficult as using rectangular coordinates directly, so weigh it yourself. Which method needs less calculation.