Poll of the Day > Math is weird.

(+) Yeah! (+)

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(x-2)(x+2) \ (x-2)

x+2 = 4

x = 2
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um X is actually a letter
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Thats not math
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FrozenBananas posted...

not math

Yes, it is. It's like a typical problem you would find from the Calculus I section of your calculus textbook explaining how limits work and whatnot. Also, the image that TC posted is incorrect notation-wise. You have to say that the bottom expression approaches four (f(x)->4) as x approaches two (as x -> 2). Alternatively, you could just write out the lim expression at the beginning of the function, write "x->2" on the bottom of it, followed by the function f(x) = (x^2-4)/(x-2).
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bro, zero divided by zero isnt 4!

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D + 10 / 6 = 3

Answer:
D = 8

Also acceptable:
8=D
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HornedLion posted...

Also acceptable:

The equality relation, as an equivalence relation, is reflexive. So yes, the penis you formed using this property is valid.
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Alternatively, you could have used L'Hopital's Rule in order to conclude that the limit is indeed four, but you probably will not learn that until your next semester. Or you could have done it via delta-epsilon proof (let epsilon = delta). Let epsilon be positive and set delta = epsilon. Then if |x - 2| < delta, then |(x^2-4)/(x-2)-4| = |(x + 2) - 4| < |x - 2| < delta = epsilon. This is the proper definition of the limit, which you might lightly touch on at the end of the limits sequence of your course. Although, it's not like I stated it properly or anything. All I did was just do a bunch of algebra and show you how the proof method works. The idea is this, I think: You can make f(x) (for x within a certain distance of, but not equal to, x = 2) as close to 4 as you like, provided you choose a sufficient distance (possibly dependent on the degree of closeness of f(x) to 4). I'm sure I didn't explain it properly, but you can find a better explanation in a textbook or online, or something. Anyway, in Advanced Calculus I, you'll be using this proof method far more often.
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HornedLion posted...

D + 10 / 6 = 3

Answer:
D = 8

Also acceptable:
8=D

8 + 1.6666..... = 3?
I don't think so.
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Blaqthourne posted...

HornedLion posted...

D + 10 / 6 = 3

Answer:
D = 8

Also acceptable:
8=D

8 + 1.6666..... = 3?
I don't think so.

He meant (D+10)/6=3
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That only is true if and only if x does not equal 2.

x is a non permissible value in that rational expression. That solution, (2, 4), is what is known as a point of discontinuity. It doesn't actually show up on the graph of that expression.

I teach high school math, this is 11th grade stuff here.
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https://www.youtube.com/watch?v=MS2aEfbEi7s" data-time="&start=42
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Math sucks!
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