# Robin Chapman

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bio website empslocal.ex.ac.uk/people/… location Exeter, United Kingdom age member for 2 years, 10 months seen Jan 10 '11 at 11:54 profile views 3,345

# 557 Actions

 Dec9 awarded Nice Answer Dec9 comment Is $\frac{e^z-1}{e^z+1}$ analytic?This is certainly homework somewhere :-) empslocal.ex.ac.uk/people/staff/rjchapma/courses/an10/an4.pdf Dec9 comment Why is it harder to prove which integers are sums of three squares rather than sums of two squares or four squares?Thanks Steven, I hope I've caught all the miscreant $n$s. Dec9 revised Why is it harder to prove which integers are sums of three squares rather than sums of two squares or four squares?corrected variables Dec9 answered Why is it harder to prove which integers are sums of three squares rather than sums of two squares or four squares? Dec8 comment Logic in the metatheoryModel theory is part of set theory, so use your favourite set axioms, eg. ZF or ZFC. Dec8 awarded Nice Answer Dec8 revised Does $R[x] \cong S[x]$ imply $R \cong S$?added content Dec8 answered Does $R[x] \cong S[x]$ imply $R \cong S$? Dec7 comment Is this definite integral really independent of a parameter? How can it be shown?You can certainly evaluate it via contour integration. Dec7 revised Proof for an integral involving sinc functioncorrected detail Dec7 answered can any continuous function be represented as a sum of convex and concave function? Dec7 revised Proof for an integral involving sinc functiondeleted 3 characters in body Dec7 comment Intersection of neighborhoods of 0. Subgroup?Roughly speaking yes, you need that $W$ contains a set $V\times V$ where $V$ is a neighbourhood of $0$ in $G$. Dec7 answered Intersection of neighborhoods of 0. Subgroup? Dec7 answered Proof for an integral involving sinc function Dec6 comment figuring out the x,y, and z rotation of a right triangle?Triangles generally have three vertices, and three angles. Dec6 answered Why is $\mathbb{C}[x,y]$ not isomorphic to $\mathbb{C}[x] \otimes _{\mathbb{Z}} \mathbb{C}[y]$ as rings? Dec5 comment Analytic Geometry | Two Planes and a Angle | Two SolutionsThat follows from orthogonality; now use $60^\circ$. Dec5 answered Invariant dimension property