61,687 reputation
136114
bio website math.ethz.ch/~blatter
location Switzerland
age 79
visits member for 4 years
seen 1 hour ago

2h
revised Let $S$ denote the set of all functions $f :\{0,1\}^4 \rightarrow \{0,1\}$. What is the number of functions from the set $S$ to the set $\{0,1\}$?
edited title
3h
revised Proof that geometric product is associative
added 60 characters in body
2d
revised How to determine whether three ellipses have at least one common intersection point or not?
added 300 characters in body
2d
awarded  Nice Answer
2d
revised What is the probability of my sum reaching exactly 10?
added 69 characters in body
2d
answered Prove that there exists no smallest positive real number
2d
answered What is the probability of my sum reaching exactly 10?
2d
answered How to determine whether three ellipses have at least one common intersection point or not?
Aug
26
answered complex analysis exercise
Aug
26
revised What is the average of no numbers?
deleted 15 characters in body
Aug
26
revised Modeling Rain on a Windshield for various Speeds using Calculus
added 63 characters in body
Aug
26
answered Number of intersections of two closed loops on a genus zero surface
Aug
26
answered What is the average of no numbers?
Aug
25
comment How to deduce a closed formula given an equivalent recursive one?
It is a fact of life that some very strange looking differential equations $y'=f(t,y)$ have a "closed form solution" (which can be found in a systematic way), whereas relatively simple recursive equations $y_{n+1}=f(n,y_n)$ don't.
Aug
25
answered Why is there no natural metric on manifolds?
Aug
25
answered If a plane intersects a regular surface at exactly one point, then it is the tangent plane
Aug
25
answered Probability of picking two letters from the word MATHEMATICAL
Aug
25
answered The set of all finite subsets of the natural numbers is countable
Aug
24
revised Calculating the number of subintervals required for the difference between the Upper and Lower Riemann sum to a particular value
added 46 characters in body
Aug
24
answered Where does the right hand rule appear in the “tensor” definition of the cross product?