Recent content by Svein
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A How does time derivative commute from one variable to another?
The impulse of an object is given by $$ m\cdot v.$$ Derive this with respect to time: $$ \frac{d}{dt}(m\cdot v) = \frac{d}{dt}(m)\cdot v+m\cdot\frac{d}{dt}(v). $$ In most cases m is constant... -
Learning Assembly and computer architecture for x86
x86 assembler relies on a lot of keywords. Here is part a conversion routine I wrote many years ago. Title IBM Color Graphics Simulation on Hercules ; .XLIST ; ESC EQU 1BH CR EQU 0DH LF EQU 0AH BS EQU 08H TAB EQU 09H NP EQU 0FFH Bigae EQU 92H...- Svein
- Post #85
- Forum: Programming and Computer Science
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I Problem in understanding instantaneous velocity
Copyied from "Real Analysis" (H.L. Royden): These are topological spaces. T_{1}: Given two distinct points x and y, there is an open set which contains y but not x. T_{2}: Given two distinct points x and y, there are disjoint open sets O_{1} and O_{2} such that x\in O_{1} and y\in O_{2}. T_{3}... -
I Convergence not defined by any metric
Copyied from "Real Analysis" (H.L. Royden): These are topological spaces. T_{1}: Given two distinct points x and y, there is an open set which contains y but not x. T_{2}: Given two distinct points x and y, there are disjoint open sets O_{1} and O_{2} such that x\in O_{1} and y\in O_{2}...- Svein
- Post #15
- Forum: Topology and Analysis
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I Convergence not defined by any metric
I seem to remember that metric is a strong topological property. For weaker topologies continuity is defined as that the inverse funcion of open sets are open. Whether this is applicable in this case I cannot say on the top of my head.- Svein
- Post #13
- Forum: Topology and Analysis
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I Do non-orthogonal coordinate systems mean dependent coordinates?
What is "orthogonality"? You need to add some structure to your space in order to define it. The usual version is a Hilbert space, where you define a "scalar product" of two vectors. If that scalar product is 0, the vectors are said to be ortogonal.- Svein
- Post #5
- Forum: Differential Geometry
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Is AI Overhyped?
If you disconnect from the Internet, can the so-called "AI" apps ace the Turing test? In 1955 the Eliza program was nearly there (no Internet then).- Svein
- Post #165
- Forum: Computing and Technology
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B Which conditions should I check to see if a quadrilateral is a square?
4 sides equal and both diagonals are equal.- Svein
- Post #12
- Forum: General Math
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B Confused about ciphers in the book 'Arithmetic for the Practical Man'
A "cypher" is another term for something that is converted from a readable format to something that is not readable. The reader then needs a "key" to convert the coded text into readable format.- Svein
- Post #11
- Forum: General Math
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I A curve that does not meet rational points
I think the relevant answer is the "bump function".- Svein
- Post #5
- Forum: Topology and Analysis
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Why Were Resistor Values Indicated by Colored Bands Instead of Printed Numbers?
Ah - colur codes. I remember way bak when TV could be repaired and often had to. A common fault in a certain model was that the cathode resistor had a tendency to burn out. The standard replacement resistor was 1kohm (brown - black- red). One low-level repair guy was red-green color blind...- Svein
- Post #19
- Forum: Electrical Engineering
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B Is Each Stage of Pascal's Triangle Special?
Also observe that 2^{n} = (1+1)^{n}=\sum_{i=0}^{n}\begin{pmatrix} n \\ i\\ \end{pmatrix} 1^{n-i}\cdot 1^{i}=\sum_{i=0}^{n}\begin{pmatrix} n \\ i\\ \end{pmatrix}- Svein
- Post #7
- Forum: General Math
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B Is Each Stage of Pascal's Triangle Special?
Look at the triangle. Observe that each element is the sum of the two elements above it (in your row, 6=1+5, 15=5+10, 20=10+10 etc.).- Svein
- Post #3
- Forum: General Math
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B Are Implication and Equivalence Interchangeable in Logic?
In predicate calculus A\Rightarrow B is defined as \neg (A \wedge \neg B) , or (using deMorgan) \neg A \vee B . Expressed in words: You cannot have A and not B, or the converse: If A is false, B can be anything.- Svein
- Post #10
- Forum: General Math
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Why do emails from my contact form bounce?
Have you tried "ping example.com"? You may not have the applicable DNS. Or does your program need to know how to access DNS?- Svein
- Post #2
- Forum: Programming and Computer Science