My Intro to Calc prof handed the class a sheet. Basically, it's a review of stuff taught in high school Pre-Cal classes. The entire point is just to see if we're ready for Intro to Calc.
A few of the questions are very easy. Others I cannot for the life of me remember how to solve.
The first one I'm stuck on: Simplify x+(1/y)/y+(1/x)
I don't remember where to start, but according to the solutions, the final answer is x/y.
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When the babel fish was in place, it was apparent Snugglits said:
The answer is x/y
Yes, but how do I get to that answer? 
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Snugglits impressed everyone with:
Simplify to x/y
...No shit. I'm just not certain where to start doing so. -_-
I was thinking of throwing the 1/y to the bottom and the 1/x to the top, making everything (x+x)/(y+y) or 2x/2y, then cancelling the twos and ending up with x/y. That just seems too easy, though, and I can't remember if you can even do that.
in general, you handle these by getting things all into *one* fraction. Pretty much any function like this can be reduced to a single fraction, by making the bottom one big fraction, and the top one big fraction.
like this:
(x+(1/y))/(y+(1/x))
make the top one fraction by multiplying the x by y/y
((x*y/y) + 1/y)/(y+(1/x))
((x*y+1)/y)/(y+(1/x))
Then do the same to the bottom, using x/x:
((x*y+1)/y)/(y*x/x+(1/x))
((x*y+1)/y)/(y*x+1/x))
Now, invert that bottom fraction:
((x*y+1)/y) * x/(y*x+1)
giving you one big fraction,
((x*y+1)x/(y*(y*x+1))
cancel, aaand..
x/y
remember, to simplify multi-level fractions, get things to have common denominators, so you can invert them.
In the beginning the Universe was created.Douglas Adams, 1952-2001
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Bent over the coffee table, Snugglits squealed:
Simplify to x/y
That reminds me of when I failed the first exam in my Calc 101 class in college. I'd already had Calc in HS, and the test was one that could be done all in your head if you knew the trick. . .but the prof had this odd grading scheme where the answer was only worth about a quarter of the points, and he awarded other points for the mythical intervening steps. It's an odd feeling to score 25% on a test where you get all the answers correct. 
He wouldn't accept that there just weren't any intermediate steps if you knew the trick, "Because you're not supposed to know that yet."
--Satan, quoted by John Milton
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A sleep deprived Bloodsage stammered:
That reminds me of when I failed the first exam in my Calc 101 class in college. I'd already had Calc in HS, and the test was one that could be done all in your head if you knew the trick. . .but the prof had this odd grading scheme where the answer was only worth about a quarter of the points, and he awarded other points for the mythical intervening steps. It's an odd feeling to score 25% on a test where you get all the answers correct.
He wouldn't accept that there just weren't any intermediate steps if you knew the trick, "Because you're not supposed to know that yet."
Did he want you to use limits? Because for some reason they build some discrete mathematics into those basic calc classes and want they really want is you to do the discrete math instead of the calculus. Snugglits fucked around with this message on 09-09-2005 at 07:15 PM.
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Quoth Snugglits:
Did he want you to use limits? Because for some reason they build some discrete mathematics into those basic calc classes and want they really want is you to do the discrete math instead of the calculus.
I forget, exactly--it's been 21 years.
It was the trick where you can just multiply the exponent by something-or-other then decrement it and, lo and behold!, you have the answer.
--Satan, quoted by John Milton
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Bloodsage had this to say about the Spice Girls:
I forget, exactly--it's been 21 years.It was the trick where you can just multiply the exponent by something-or-other then decrement it and, lo and behold!, you have the answer.
Right, so f(x)=x^2, f'(x)=2x. Yeah, you can just write that out, and yeah he wanted you to do the long, boring limits.
That guy still kind of sounds like an ass.
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Quoth Snugglits:
Right, so f(x)=x^2, f'(x)=2x. Yeah, you can just write that out, and yeah he wanted you to do the long, boring limits.That guy still kind of sounds like an ass.
Yes, and yes.
--Satan, quoted by John Milton
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Mr. Parcelan had this to say about pies:
Math is for geeks
Have you ever killed a man? Snugglits fucked around with this message on 09-09-2005 at 07:49 PM.
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Verily, the chocolate bunny rabits doth run and play while Naimah gently hums:
Yea, doing derivities by the definition is lame. But it kinda helps to see where everything is coming from and that it isn't just all magical.
I just wished he'd made it clear in the instructions what method he wanted us to use. "Show your work," is hardly direction to use a particular method.
No, I'm not still bitter.
--Satan, quoted by John Milton
Noxhil2 fucked around with this message on 09-09-2005 at 07:58 PM.
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Verily, Snugglits doth proclaim:
Have you ever killed a man?
With math?
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Mr. Parcelan wrote this then went back to looking for porn:
With math?
No.
With your bare hands.
