Take the formula for the area of a cylinder. If you study it and “break it apart”, you will find that it is simply the area of two circles (top and bottom) and a rectangle (side cut and rolled out). Once you understand that, you never need to memorize the formula for a cylinder. You also know how to compute the area of a cylinder with one (or both) tops “missing”.
Somewhat related, do not get behind. Once you “get behind”, you “panic” and “hurry” to catch up. You skip, memorize formulas, copy homework, etc. That is a sure recipe for disaster in the future.
In general, you should not memorize a formula. You should go through the derivation, understand where it came from, where it is used, and you will never forget it. That is not to say that you should not “memorize” concepts--but you should always understand them.
Do not neglect your homework. Homework is designed to reinforce your grasp of the concepts. It was always amazing to me that students thought they were “fooling me” when they copied someone else’s homework. To tell you the truth, I didn’t care. The homework was for THEIR benefit, not mine. (Hell, if they didn’t do it, I didn’t have to correct it.) When I see folks on Yahoo asking “us” to do their homework for them, I just pass on by. It’s usually fairly obvious. The funny thing about it is that they think they are being “smart” and “getting by”. Someday, they will apply for a job, and they will be given a test--and there will not be anyone to copy from. How they perform on that test will determine whether they get put behind a desk or behind a broom.
Finally, you should never go to a math lecture with the attitude “teach me”. You should have reviewed the lesson the night before, and enter the classroom with the attitude, “I’ve got a few questions I want to ask.” or, “I want clarification of certain things I read the night before.” If you do that, the lecture will make just a helluva lot more sense.
Good luck,
Tony