1. ****in sucks brah. Hard way to learn a lesson about a specific prof. At least now you know to do everything exactly his way.
You could always take it up with the dean, I mean, a right answer is a right answer! amirite?!?!

2. Originally Posted by Muckle_Ewe

So...

And since you can interchange the sum and integral we get...

Now since k is an integer you'll find that when you integrate cos(kx) between 0 and pi it should come out to be 0 leaving the answer as pi.
thanks for the help. i remembered the last line of that right after i started doing it. thanks man

3. Originally Posted by moosecakes4all
****in sucks brah. Hard way to learn a lesson about a specific prof. At least now you know to do everything exactly his way.
You could always take it up with the dean, I mean, a right answer is a right answer! amirite?!?!
Thing is I've had him for two algebra classes before and he wasn't even near this bad. I made an A in his class in the spring, I had to bust my ass for it, but it wasn't this crazy.

I can see how me getting the right answer with no work done would merit me not getting credit, but it was pretty ****ing obvious that I knew the concept and how to use it.

If I don't get at least a B I'm definitely taking it up with the dean. I requested a copy of this test because we had to turn them back for some reason. Hopefully I can show it to him.

And for reference, all points where where the slope of f(x) = 0 is the same where f'(x) = 0, right?

4. Originally Posted by DangerDan
http://forum.bodybuilding.com/showth...#post551947533

Are these guys serious? Is (x^2-1)/(x+1) really discontinuous? Wtf man?
yes u cannot divide by zero

i said it at first then tried to get myself to change the answer to agree with you guys but then i realized im in vector calculus if i don't know this **** then thats bad lol

5. Originally Posted by DangerDan

And for reference, all points where where the slope of f(x) = 0 is the same where f'(x) = 0, right?
yes that is the definition of a derivative

6. Originally Posted by charity4thepoor
yes u cannot divide by zero

i said it at first then tried to get myself to change the answer to agree with you guys but then i realized im in vector calculus if i don't know this **** then thats bad lol
Wtf man?

How come I didn't learn this in my calc class?

What if 0/0 = one? **** would be crazy.

7. Originally Posted by DangerDan
Wtf man?

How come I didn't learn this in my calc class?

What if 0/0 = one? **** would be crazy.
lol should have learned that in pre-calc brah. if 0/0=1 that would also imply that infinity/infinity=1

you will learn towards the endish when you talk about l'hopital's rule why it is important. (although you don't use it in this situation i don't know why i brought it up in the other thread)

8. Originally Posted by DangerDan
Wtf man?

How come I didn't learn this in my calc class?

What if 0/0 = one? **** would be crazy.
What if 1/1=0? **** would also be crazy.

9. Originally Posted by charity4thepoor
lol should have learned that in pre-calc brah. if 0/0=1 that would also imply that infinity/infinity=1

you will learn towards the endish when you talk about l'hopital's rule why it is important. (although you don't use it in this situation i don't know why i brought it up in the other thread)
I know that x/0 = undefined, but I always thought that 0/0 was just 0.

I learned in statistics today that 0! is 1. That's pretty weird too. lol.

10. Originally Posted by DangerDan
http://forum.bodybuilding.com/showth...#post551947533

Are these guys serious? Is (x^2-1)/(x+1) really discontinuous? Wtf man?
Ok...

I'm having a mind melt down trying to sort this all out.

I'll just rip this off wiki. My knowledge of continuous functions isn't solid so hopefully MiscMath can sort this out.

If two functions f and g are continuous, then f + g, fg, and f/g are continuous. (Note. The only possible points x of discontinuity of f/g are the solutions of the equation g(x) = 0; but then any such x does not belong to the domain of the function f/g. Hence f/g is continuous on its entire domain, or - in other words - is continuous.)

But what I'm thinking is...

Say you have some function. f(x) = x. Pretty obvious this is continuous.

But do we change this into a discontinuous function by multiplying by .

It doesn't seem to make much sense to me... Are x and different functions?

11. Originally Posted by Muckle_Ewe
It doesn't seem to make much sense to me... Are x and different functions?
Yes. Both are straight lines with a slope of 1, but x^2 / x has a removable discontinuity at the origin.

12. Originally Posted by DangerDan
I know that x/0 = undefined, but I always thought that 0/0 was just 0.

I learned in statistics today that 0! is 1. That's pretty weird too. lol.
yea man if 0! didn't equal 1 then no probabilities would make sense. i think it's just the way 0! is defined

13. Originally Posted by charity4thepoor
yea man if 0! didn't equal 1 then no probabilities would make sense. i think it's just the way 0! is defined
Yeah, that's what I was reading on the internetz. Pretty interesting.

14. So then is every rational function with the denominator able to equal to zero discontinuous at the point where the denominator is 0?

15. Originally Posted by DangerDan
So then is every rational function with the denominator able to equal to zero discontinuous at the point where the denominator is 0?
yes sir

16. Originally Posted by DangerDan
Yeah, that's what I was reading on the internetz. Pretty interesting.
A quick not very rigorous proof.

n! = n(n-1)!

=> (n-1)! = n!/n

Set n=1

0! = 1!/1 = 1

Hence 0! = 1

17. Originally Posted by charity4thepoor
yes sir
That's so weird. I've never learned that. Ridiculous.

18. Originally Posted by Muckle_Ewe
A quick not very rigorous proof.

n! = n(n-1)!

=> (n-1)! = n!/n

Set n=1

0! = 1!/1 = 1

Hence 0! = 1
Very nice. That's pretty cool.

19. Originally Posted by DangerDan
Got a 65% on mine and the class average was a 67%. No one got an A, 3 got a B, 3 got a C, 3 got a D, and 6 got Fs.
I think we had 2 perfect As, the rest were Bs-Fs, lots of Ds and Fs. I think like 1/3rd the class was missing today. Guessing they dropped.

Originally Posted by DangerDan
Wtf man?

How come I didn't learn this in my calc class?

What if 0/0 = one? **** would be crazy.

20. Originally Posted by Errorist
I think we had 2 perfect As, the rest were Bs-Fs, lots of Ds and Fs. I think like 1/3rd the class was missing today. Guessing they dropped.

Hell yeah, a lot of my class probably won't show up on Tuesday. Drizzopped.

And yeah, I'm aware of the whole dividing by zero thing. It just seems weird that 0/0 would even be dividing by zero because 0 isn't anything. So you're not really dividing anything by zero.

21. Originally Posted by DangerDan
And yeah, I'm aware of the whole dividing by zero thing. It just seems weird that 0/0 would even be dividing by zero because 0 isn't anything. So you're not really dividing anything by zero.
Yea I don't really get it either.

1/0 = Should still be 1 because you're dividing by nothing, so you still have the whole thing that you're dividing.
0/2 = Shouldn't be possible because how can you divide nothing by something? Doesn't make sense.

Dunno, weird logic.

22. Originally Posted by Errorist
Yea I don't really get it either.

1/0 = Should still be 1 because you're dividing by nothing, so you still have the whole thing that you're dividing.
0/2 = Shouldn't be possible because how can you divide nothing by something? Doesn't make sense.

Dunno, weird logic.
Something wrong with the way youre thinking about this. If you split a dollar between no people, how much money to they get? Doesn't make sense, there is no "they".

Mathematically, if 1/0 is not 0, then all numbers are equal. Proof: Exercise . You can define a system of numbers with this property, but it isn't very interesting.

0/2? If john and Alice make x dollars and split it, they each get x/2 dollars. They end up getting 0/2 dollars a piece. But since they made a total of 0 dollars, 0/2=0.

23. Originally Posted by MiscMathematician
Something wrong with the way youre thinking about this. If you split a dollar between no people, how much money to they get? Doesn't make sense, there is no "they".

Mathematically, if 1/0 is not 0, then all numbers are equal. Proof: Exercise . You can define a system of numbers with this property, but it isn't very interesting.

0/2? If john and Alice make x dollars and split it, they each get x/2 dollars. They end up getting 0/2 dollars a piece. But since they made a total of 0 dollars, 0/2=0.
What do you get when you divide something by nothing?
1/0 = 1
2/0 = 2
3/0 = 3
You get exactly what you started out with, because you haven't divided it by anything. There's nothing to divide the original number by, so it's still a whole number.

What do you get when you divide 0 by something? You can't because there wasn't anything to divide in the first place. It's impossible.

These 2 rules really need to be switched.

24. Originally Posted by Errorist
What do you get when you divide something by nothing?
1/0 = 1
2/0 = 2
3/0 = 3
You get exactly what you started out with, because you haven't divided it by anything. There's nothing to divide the original number by, so it's still a whole number.

What do you get when you divide 0 by something? You can't because there wasn't anything to divide in the first place. It's impossible.

These 2 rules really need to be switched.
You can't be serious. Division is the inverse of multiplication. 0/2 should return what you have to multiply 2 by to return 0. That would be 0. 2/0 should return what you have to multiply 0 by to return 2. There's nothing big enough, so it's infinite.

25. Originally Posted by Greg1983
You can't be serious. Division is the inverse of multiplication. 0/2 should return what you have to multiply 2 by to return 0. That would be 0. 2/0 should return what you have to multiply 0 by to return 2. There's nothing big enough, so it's infinite.
If I cut 1 pizza into 0 slices, and eat them, how much pizza do I have left? I end up with 1 whole pizza and I'm still hungry.

Also, I can't cut a pizza into slices that I don't have, it's impossible to do.

26. Originally Posted by Errorist
If I cut 1 pizza into 0 slices, and eat them, how much pizza do I have left? I end up with 1 whole pizza and I'm still hungry.

Also, I can't cut a pizza into slices that I don't have, it's impossible to do.
When you're dividing by numbers smaller than 1, you can't think of it as dividing up the pizza. I wish I could take a pizza, decide I'm cutting it into half a slice, and wind up with 2 pizzas. That would rule. Think of it like this.

How many slices of size 0.5 can you pull out of the pizza? 2. 1/0.5 = 2.
How many slices of size 0.1 can you pull out of the pizza? 10. 1/0.1 = 10.
How many slices of size 0 can you pull out of the pizza? As many as you want. Go for the rest of your life if you want. And that's why it's infinite.

27. the **** is going on in here?

28. Originally Posted by Greg1983
How many slices of size 0 can you pull out of the pizza? As many as you want. Go for the rest of your life if you want. And that's why it's infinite.
So dividing by 0 is possible, 1/0 = infinite.

Originally Posted by charity4thepoor
the **** is going on in here?
lol

29. Originally Posted by Errorist
So dividing by 0 is possible, 1/0 = infinite.
As possible as infinite is, anyways.

30. Originally Posted by Errorist
If I cut 1 pizza into 0 slices, and eat them, how much pizza do I have left? I end up with 1 whole pizza and I'm still hungry.

Also, I can't cut a pizza into slices that I don't have, it's impossible to do.
If you have a pizza and cut it into zero slices? A pizza already is "one slice." So then, you couldn't have it to being with if is cut into 0 slices. Secondly when you add up all your parts of the "pizza" (mathematicians would call this a partition) you need to get back the whole "pizza". If 1 pizza is divided into 0 slices, this means that you now HAVE 0 slices of pizza. So adding up all 0 slices should give you what you started with... Again, it makes no sense.

Originally Posted by Errorist
So dividing by 0 is possible, 1/0 = infinite.
No, but the limit as x approaches 0 of 1/x^2 is infinity. "1/0 = infinity" is okay for calculus I suppose, but I wouldn't write it, just think it. Here's one example: what is the limit as x goes to 0 of 1/x? Its not infinity.

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