Quadratic nightmares

[cjsmith]

How does one solve a quadratic equation quickly? (Without sacrificing accuracy, of course, and without making it more likely that an arithmetic goof will creep in.)

I know how to use the quadratic formula, but I'm slow and methodical. On a test, minutes count. I've been warned that on the upcoming chemistry exam, seconds may count. This one has been announced as "hard" and "if you haven't done all the practice problems three times over, you won't have time to complete the test". It's going to be FULL of this stuff (for equilibrium calculations). I don't have time between now and the test to do all the practice problems three times over, not if I want sleep too.

How do you solve these dang things FAST?

Oooo. Are there calculators that just do this for you, once you've set up the equation? If so, I'd better go get one. If that's what other students have, I'd be a fool to handicap myself.

Comments

[cjsmith.livejournal.com]

Given what I see around me, I suspect that's right. There are students in my classes who listen, who do the work, and who are doing very well. They're rare. If I were a teacher I'd be at my wits' end with most of the class.