Recent content by reb659
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Complex analysis antiderivative existence
Homework Statement a) Does f(z)=1/z have an antiderivative over C/(0,0)? b) Does f(z)=(1/z)^n have an antiderivative over C/(0,0), n integer and not equal to 1. Homework Equations The Attempt at a Solution a) No. Integrating over C= the unit circle gives us 2*pi*i. So for at least one...- reb659
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- Analysis Antiderivative Complex Complex analysis Existence
- Replies: 1
- Forum: Calculus and Beyond Homework Help
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Differential geometry acceleration as the sum of two vectors
How so?- reb659
- Post #6
- Forum: Calculus and Beyond Homework Help
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Differential geometry acceleration as the sum of two vectors
Basically the main question I have is if the only way to do this would be to explicitly calculate the expression for N(t).- reb659
- Post #4
- Forum: Calculus and Beyond Homework Help
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Differential geometry acceleration as the sum of two vectors
So I should able to write a(1) as a linear combination of T(1) and N(1), correct? But how do I get N(t)? Taking derivatives of T(t) is very messy and the professor said it didn't involve any long calculations. Furthermore we haven't learned about the binormal and normal in this section yet...- reb659
- Post #3
- Forum: Calculus and Beyond Homework Help
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Differential geometry acceleration as the sum of two vectors
Homework Statement a(t)=<1+t^2,4/t,8*(2-t)^(1/2)> Express the acceleration vector a''(1) as the sum of a vector parallel to a'(1) and a vector orthogonal to a'(1) Homework Equations The Attempt at a Solution I took the first two derivatives and calculated a'(t)=<2t, -4t^2, -4/(2-t)^(1/2)>...- reb659
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- Acceleration Differential Differential geometry Geometry Sum Vectors
- Replies: 5
- Forum: Calculus and Beyond Homework Help
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Cauchy riemann equations and constant functions
Ah yes, I meant unit circle. I was thinking the domain would need to have restrictions because I thought I proved it yet found a counterexample at the same time. But for the original problem: Let f=U + iV. We have |f|=c for some constant c. |z|^2=zz*, so we have |f|^2=c^2 which implies...- reb659
- Post #5
- Forum: Calculus and Beyond Homework Help
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Cauchy riemann equations and constant functions
But what about the function f(z)=z=x+iy? Isn't that function analytic on the say, unit disk with a constant modulus but f is not constant?- reb659
- Post #3
- Forum: Calculus and Beyond Homework Help
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Cauchy riemann equations and constant functions
Homework Statement Let f(z) be analytic on the set H. Let the modulus of f(z) be constant. Does f need be constant also? Explain. Homework Equations Cauchy riemann equations Hint: Prove If f and f* are both analytic on D, then f is constant. The Attempt at a Solution I think f need be...- reb659
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- Cauchy Constant Functions Riemann
- Replies: 5
- Forum: Calculus and Beyond Homework Help
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Linear equations, solution sets and inner products
Homework Statement Let W be the subspace of R4 such that W is the solution set to the following system of equations: x1-4x2+2x3-x4=0 3x1-13x2+7x3-2x4=0 Let U be subspace of R4 such that U is the set of vectors in R4 such the inner product <u,w>=0 for every w in W. Find a 2 by 4...- reb659
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- Linear Linear equations Sets
- Replies: 2
- Forum: Calculus and Beyond Homework Help
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Open and closed intervals and real numbers
Yay! How exactly does uniqueness follow though? It seems like its trivial to prove.- reb659
- Post #7
- Forum: Calculus and Beyond Homework Help
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Open and closed intervals and real numbers
So far: Since S is bounded above and below, by Dedekind completeness there exists a supremum of S. Call it b. Again by dedekind completeness we can say there exists an infimum of S. Call it b. By definition of sup and inf, a<b. We are left to show a,b are unique and that S is exactly one...- reb659
- Post #5
- Forum: Calculus and Beyond Homework Help
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Open and closed intervals and real numbers
Good idea. Isn't it an axiom that if a nonempty subset of R has an upper bound, then it has a least upper bound/sup(S)?- reb659
- Post #3
- Forum: Calculus and Beyond Homework Help
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Open and closed intervals and real numbers
Homework Statement Show that: Let S be a subset of the real numbers such that S is bounded above and below and if some x and y are in S with x not equal to y, then all numbers between x and y are in S. then there exist unique numbers a and b in R with a<b such that S is one of the...- reb659
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- Closed intervals Numbers Real numbers
- Replies: 7
- Forum: Calculus and Beyond Homework Help
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Additive functions, unions, and intersections.
I am such an idiot. I tried it before representing the left hand side as a union of disjoint sets but for some reason I didn't bother manipulating the right hand side in the same way. Thanks a ton!- reb659
- Post #3
- Forum: Calculus and Beyond Homework Help
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Additive functions, unions, and intersections.
Homework Statement A function G:P--->R where R is the set of real numbers is additive provided G(X1 U X2)=G(X1)+G(X2) if X1, X2 are disjoint. Let S be a set, Let P be the power set of S. Suppose G is an additive function mapping P to R. Prove that if X1 and X2 are ARBITRARY(not necessarily...- reb659
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- Functions
- Replies: 2
- Forum: Calculus and Beyond Homework Help