Math Test, Please Help
- Thread starter Nuka-sama
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ShannonCT
Deity
ShannonCT
Deity
Thank you
No problem. I do this for a living.
Leifmk
Deity
Huh. I have a grad-school degree in math (from, damn, nearly ten years ago) and that's news to me. Maybe a regional/style thing?
Irish Caesar
Yellow Jacket
I don't know; I learned it in fifth grade in Massachusetts. Hasn't really come up since.
Leifmk
Deity
fractions are rational. if there is a radical on the bottom, it's no longer rational. that's they can't be on the bottom.
Ah, not exactly. Fractions certainly don't have to be rational (if you take math at higher levels you'll be knee deep in counterexamples) and square roots/radicals can be rational numbers (though in that case you'll usually simplify them so the radical symbol goes away).
Though you're on to something when you connect fractions with the concept of rational numbers. The actual definition of a rational number is any number which can be written as a fraction a/b where both a and b are integers (and b is not zero).
Gogf
Indescribable
Do you teach Algebra?
Tomoyo
Fate
I think that it's just easier to work with rational denominators, so students are taught to avoid radicals in the denominator. Besides, if one is "stuck", rationalizing the denominator can make things much clearer.
they do so have to be rational! it's just the laws of math
i get higher levels of math next year
pboily
fingerlickinmathematickin
[wiki=Fraction_ring]But wait, there is more...[/wiki]
ShannonCT
Deity
Algebra, Geometry, Trigonometry, Calculus, Statistics...
Gaius Octavius
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I haven't rationalized a denominator in quite some time... at least, not that I can remember. A lot of people, even math professors I've run into, don't seem to mind if you leave a radical in the denominator.
civverguy
Emperor
Do you have more problems? I'm taking a standardized test this week so I need some practice in math.
Gaius Octavius
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What kind of problems will you be up against?
It's just the high school teachers who care about such things. They have tons of silly rules they can't justify. Usually people in universities are much more liberal in their presentation. Actually, my first thought when I saw the question was "What am I supposed to do?". If I did some calculations and arrived to a conclusion sqrt5 +1/sqrt5, I would be completely satisfied with it.
Maybe the reason behind this particular silly rule is that as 6/sqrt5 is just a fraction, expression (6sqrt5)/5 can be understood as some mulitiple of 1/5, and hence it's quantity is more obvious.
Golden Touch
Prince
do your own work you lazy little punk! what happens when you get into the exams and cant do it hey?!
Mirc
Not mIRC!!!
Well, here we call this rationalizing (rationalizare) and if you completed an exercise, no matter how complicated it is, and you leave that in the denominator, it will be considered like you did not finish the exercise.
