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6h
comment Probability with Primes
Never mind, I just realized that 1) you wrote $0\le a\le6$ when you meant $0\le c\le6$, and OP wrote $8+5+7$ when what was meant was $8+7+5$.
6h
comment Probability of guessing Date of Birth
Suppose you can estimate a person's age to within $\pm5$ years. The number of days in 10 years is 3,650 (to three significant figures), so your chances of getting it exactly right must be at least 1 in 3650. If the probability is concentrated toward the center of the 10-year range, maybe your chances are as good as 1 in a thousand.
6h
revised Prerequisites of Vector Calculus for Freshman
typos
6h
revised Incentre and excentre of a triangle
edited tags
6h
revised Induction inequality on sum of reciprocals
more informative title, typo
6h
comment Trigonometric AP relation on sides of a triangle
Ah, Ramanujan's textbook. The angles, by the way, are $x<90-2x<90+x$, so you get $$\cot(x/2)+\cot((90+x)/2)=2\cot(45-x)$$
6h
comment Simon Letherman, Dierk Schleicher, and Reg Wood 1999 paper on the 3n+1 problem, further results
If you have access to a university library, and they have access to MathSciNet (Math Reviews online), then you can find the review of that paper, and see whether any later papers have cited it.
6h
comment Trigonometric AP relation on sides of a triangle
What's the source of this problem, please?
6h
comment Simon Letherman, Dierk Schleicher, and Reg Wood 1999 paper on the 3n+1 problem, further results
The place to start with all Collatz questions is the book by Lagarias.
6h
answered Logic of numerical series
6h
comment common terms problem
Finding terms in both of a pair of recurrence sequences can be a difficult problem. See for example dml.cz/dmlcz/137484 and the references there.
6h
comment common terms problem
The question is not clear. Are you asking for $m$ such that $x_m=x_m'$? or are you asking for $j$ and $k$ such that $x_j=x_k'$?
7h
comment Probability with Primes
And that's not all.
7h
revised Definite integral, quotient of logarithm and polynomial
more informative title
7h
comment Number of possible ways to give change for 2 pounds
No, the equation $a+b+c+d=100$ is not directly relevant to the equation $200a+100b+50c+20d=200$. Also, we have been asked not to discuss Project Euler questions here.
7h
revised Is the function $f(x) = 1/x$ continuous?
typos, more informative title
12h
comment What does this mean?
A $k$-tuple is an ordered list of $k$ numbers. Also, you have probably left out the word "integers" after "non-negative".
12h
revised Minimum speed using calculus
edited tags
12h
revised How to prove that something is finite
edited tags
13h
comment Minimizing sum of functions implies minimizing their squares, maximizing the sum of the inverses?
Are you still here?