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Friday, February 20th, 2009 05:23 pm
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.
Saturday, February 21st, 2009 01:43 am (UTC)
Graphing calculators are amazing little things. Even a decade ago I had a TI-89 that did symbolic manipulation (ie algebra, without resorting to numbers). It'll solve them faster than you can type them in...
Saturday, February 21st, 2009 01:58 am (UTC)
Awesome. Half the students in class have big fat fancy calculators, so I'd wager half the students in class are not punching in "b squared minus 4 a c" etc by hand and potentially goofing it up. I clearly need to upgrade.