Question

Go to this site: http://tutorial.math.lamar.edu/Classes/CalcIII/Limits.aspx
Check out example c, explain to me how and why he gets 0 in the first 2 limits when he has a situation of 0/x^4 and 0/y^4 where x and y goes to 0.

Answer 1

Come on, it's saturday night, you dont go out and do stuff, you do math stuff instead... :P

Answer 2

Over here, it's actually early Saturday afternoon...lol.
Based on what he says, I think he's saying "As x approaches 0, it's 0, and as y approaches 0, it's 0, but let's look at how they both approach 0 at the same time." And by approaching how they both approach zero at the same time, you can see how the function behaves along the line y=x. Now, if you analyze it along y=x, you can substitute x for each y in the function, and you end up getting x^4/4x^4 - which simplifies to 1/4.

Answer 3

It's kinda awkward to describe in words, but does it make sense conceptually?

Answer 4

makes sense to me

Answer 5

It sure makes sense at that approach, but he approaches it at 2 other ways in the same example, all 3 are necessary to evaluate the limit at that point. I do fully understand that 3rd way which you described, but the question as said is the first 2 approaches. Anyone who understand those? lim (x,0) -> (0,0) and lim (0,y) -> (0,0)