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I teach math at St. John Fisher College in Rochester.


12h
comment After how many steps can compositions of $x\mapsto x+1$ and $x\mapsto x^2+1$ produce the same result starting from $1$ and $3$?
If we arrive at a pair $(x,x)$ one can show we have not just applied both rules in either order, [i.e. first P,Q and then Q,P or vice versa) else one would have squares at difference 1 or 2. Maybe there's something using that...
2d
comment If each uncountable set $T$ has a countable subset, can we form $T$ by a union of countable subsets?
Statement 2 must be adjusted to: A countable union of countable sets is countable. If arbitrary unions are allowed, any set $X$ is the union of the collection of its singletons $\{x\},$ and each set of this union is countable.
2d
comment interpolation the points that are so near
Maybe if you put the complete problem here, someone could help out. As it is there isn't much to go on.
2d
answered To prove a hyperbola being orthogonal via parametric equations
2d
comment What is easiest way to know it the large number divisible by 57
Seems it must be "divisible by 57", and that the use of "divided" in the question can be explained by language problem.
Aug
19
comment Is it absolutely certain that repeated random selection of integers from 0 to 100 will eventually select every integer?
What does one do on later layers if the roll lands you at an already circled number? Roll again? If so there could possibly arise cases where there is a surviving spot one could arrive at on a given layer, and all six spots after it might already be circled. In that case the process must have no continuation. On the other hand, maybe the rule is to skip over already circled ones...
Aug
16
revised Prove a set which conatins one point from each class in circle of circumference 1 is nonmeasureable
added 316 characters in body
Aug
16
answered Prove a set which conatins one point from each class in circle of circumference 1 is nonmeasureable
Aug
15
revised Minimum of function of x and y
added 129 characters in body
Aug
15
revised Minimum of function of x and y
added 951 characters in body
Aug
15
answered Minimum of function of x and y
Aug
13
answered Parametrization of curve
Aug
13
comment Cubic polynomial equal to a cube
If the form of these functions of $n$ are known it might improve the question, since as it is it includes maybe too nearly the general situation, and specific info might help in a solution.
Aug
13
comment Cubic polynomial equal to a cube
Suggested rewording: where a,b,c,d are integers divisible by n.
Aug
13
comment Which number remains alive?
Actually that $f(n)$ is odd is clear since in round one all the evens get killed, for any $n.$
Aug
12
comment System of Diophantine Equations
@VarunIyer In your example the smallest two don't differ by $1$.
Aug
12
answered Simplifying a square root of a square
Aug
12
comment Finding the region of integration
As specified in this post, the semicircle might be "above or below" the line $y=x$ (which might make a difference).
Aug
12
revised Which number remains alive?
added 337 characters in body
Aug
12
comment Proving that 0 * x = 0 using only first order logic
What is the definition of $a*b$ you are using?