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visits member for 1 year, 7 months
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Apr
7
comment How many ways to add to 21?
@NikhilMahajan,I want to know the process for answering this particular question. Full working out is expected from a good answer, as demonstrated by the accepted answer, hence I do not need to specify in the question that I want working to be shown.
Apr
7
comment How many ways to add to 21?
No this isn't homework, and I know the answer is 880, but what is the process to figure it out?
Apr
7
comment A proportionality puzzle
you misunderstood my point. You said that they clearly round up because 5/2 is rounded up. In fact most countries will round up 5/2 but this doesn't mean they will clearly round up 10/3. Therefore if it is given that they round 5/2, it is no indication that they will round up 10/3.
Apr
7
comment A proportionality puzzle
The fact 2.5 rounds to 3 doesn't mean that 3.33 rounds to 4, since most mathematicians will round up .5 and greater, but will round down anything less than .5
Oct
2
comment Surprising identities / equations
How is this formula not immediately obvious?
Sep
29
comment closed form $f_n=\sqrt{2f_{n-1}}$ ?
So f_1 = 2^(1 + 3/4) ?, but I thought f_1 was 2^(1/2)
Sep
29
comment Surprising identities / equations
This topic seems very intriguing, so thanks for posting +1.
Sep
28
comment Surprising identities / equations
@DanielV, it does lead to a paradox. The sum from 1 to infinity of 2^k = 2 + 2 + 2 + 2 etc. = -1 (our assumption). Now 2 = 1+1. Therefore 1 + 1 + 1 + 1 + 1 = -1. But the sum from 1 to infinity of 1^k = -1/2.
Sep
28
comment Surprising identities / equations
How can the sum from 1 to infinity of positive integers lead to a negative number?
Sep
11
comment Blue eyes: a logic puzzle
@IttayWeiss, what is an example of a harder logic problem?
Feb
6
comment Find a function that that makes the value of this improper integral equal to 1.
Thanks for your answer.
Feb
6
comment Find a function that that makes the value of this improper integral equal to 1.
I wasn't sure about the title. Please feel free to correct.
Feb
1
comment How is this linear 2nd-order ODE solved?
My solution accidentally solved for equation (11) instead of (14) oops
Feb
1
comment How is this linear 2nd-order ODE solved?
Hint: Equation (5) in the paper is wrong. The subscript for phi should be k, not n.
Oct
19
comment Successive Bounces of Ball Paradox
Could it be resolved if the balls height is assumed to be fixed for all bounces?
Oct
18
comment Successive Bounces of Ball Paradox
Thanks Sam, your answer appears to have resolved the apparent paradox.
Oct
18
comment Successive Bounces of Ball Paradox
My argument for method 2 is like this. Let's assume velocity is 2m/s. Distance = 2*t. After 3 seconds, Distance = 2*3 = 6m, exceeding 2.
Oct
18
comment Successive Bounces of Ball Paradox
Argument for Method 2: Speed = Distance/time. Distance = Speed*Time. Speed is constant. There is no upper bound on time, and therefore no upper bound on distance.
Oct
18
comment Successive Bounces of Ball Paradox
But Method 1 is wrong.
Oct
18
comment Successive Bounces of Ball Paradox
Yes my previous comment was incorrect.