1. I know you can't, so I'll teach you the first trick. Copy the theme expression. For example, the solution is calculated from the known AB=CD, AB is the diameter, CD is also the diameter ... everything you know that can be calculated! (generally used when absolutely not! )

2. Summarize the necessary elements, such as the requirement of y = ax 3+2x 2+C. To find the minimum value, you need to know the coordinates of the minimum value formula y = (4ac-b 2)/4a, and then find a and c, so the second measure is to work out the conditions under which the answer is valid, and then deeply contact how to meet the requirements of the topic, so the second measure is to follow the first measure, or maybe.

3. The third measure is to overcome problems and learn to contact. Every element should have its function and effect when it is connected. Find relevant formulas, calculate conclusions, and find shortcuts to solving problems. This depends on the usual practice and foundation.

4. Write the answer directly without analyzing the process, and deduct 2 points even if the process is wrong. The fourth measure is harmful, but very useful.