Math Problems for Credits (The Game)

[Roy Campbell]

Re: Math Problems for Credits (The Game)

Correct. 1,000 credits is coming your way....

Edit: sent

[GuidoHunter]

Re: Math Problems for Credits (The Game)

Uh, zero? You're asking for an infinitesimally small number that has no actual value, only a limit which tends to zero.

--Guido

http://andy.mikee385.com

[madmatt621]

Re: Math Problems for Credits (The Game)

What's the area under the curve 1/x from 1 to a where a > 1?

a) 1; b) 3/2; or c) -2/3

[bluguerrilla]

Re: Math Problems for Credits (The Game)

Sorry, I should have been more clear:

What's the area under the curve f(x) = 1/x from x = 1 to x = a and a > 1.



For a follow up question that's worth 2234 credits:

What's the area under the curve f(x) = 1/x from x = -a to x = a for any a in element of the reals and why?

(follow up question is hard)

[GuidoHunter]

Re: Math Problems for Credits (The Game)

Are you looking for ln(a)-ln(1) = ln(a)? Because without a defined value for a, no numerical value is possible.

Follow-up: zero? It's an odd function.

--Guido

http://andy.mikee385.com

[madmatt621]

Re: Math Problems for Credits (The Game)

Finally a thread where Guido can show off his mad math skills.

[bluguerrilla]

Re: Math Problems for Credits (The Game)

Yep, I was kinda wanting to see if anyone had had calc.

For the follow up the answer is only zero if you choose the integral's principal value. Principal value meaning that you choose to have the contribution from the right and the left of the integral reach zero at the same rate.

Consider breaking up the integral into two pieces, one from the left to zero and one from zero to the right. Now it's obvious we have -inf+inf which isn't well defined unless we know at which rate the two pieces reach infinity.

It was kind of a trick question, which is why I said it was harder.


I'll also quit posting problems that require higher level math than (and not including) derivatives.

[madmatt621]

Re: Math Problems for Credits (The Game)

I'll post one.

EDIT:

A dog is inside a yard that is 100 feet by 100 feet. He is chained to one wall, at the midpoint of the wall. His chain is 100 feet long. What is the total area the dog is able to access inside the yard?

[bluguerrilla]

Re: Math Problems for Credits (The Game)

Most of the yard, Pi*10000/6 + 2500 Sqrt[3] ft^2?

[madmatt621]

Re: Math Problems for Credits (The Game)

Most of the yard, Pi*10000/6 + 2500 Sqrt[3] ft^2?

Your turn.