The absolute-value tag has no wiki summary.
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Finding absolute max and min values of function
Function given as $f(x,y) = 3x^2 + 2xy^2$. If $(x,y)$ lies in the region inside including edges of the triangle in the first quadrant given by $x\ge0, y\ge0, y\le2-x$. Reduce $f$ to a single variable ...
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1answer
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Intersection of a point and absolute value function contained within a circle
I'm attempting some crazy ideas while programming a game and ran into the following math problem that has been bugging me for a few days:
Given a unit circle and a random point $P$ within the circle, ...
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Absolute of a trig function
Consider the function $$f(x) = 1\dfrac{1}{2} - 3\sin \left(\dfrac{1}{2}x \right). $$
I need to find the absolute of this function, which to my eye would just be
$$ f(x) = 1\dfrac{1}{2} + 3\sin ...
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Proof that there's a unique division quaternion algebra over a locally compact field?
There are many proofs that there is a unique division quaternion algebra over a locally compact field that is not $\mathbb{C}$. For instance this set of notes/book by John Voight contains two proofs: ...
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Fields with their own absolute value
Let $F\hspace{.02 in}$ be a field. $\:$ Let $E\hspace{.02 in}$ be a non-zero subring of $F$.
Let $\hspace{.03 in}\leq\hspace{.03 in}$ be a total order on $E\hspace{.02 in}$ that makes $E\hspace{.02 ...
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Calculation of the sub gradient of the first norm of a matrix
Lets say I have a matrix X and its first norm $||X||_1$. How do I calculate the subgradient of this norm with respect to matrix X itself.
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Continuous, differentiable, continuously differentiable
I came across the following problem:
Let $\alpha \in \mathbb R$. Where is the function continuous, differentiable, continuously differentiable?
$$f(x) =
\begin{cases}
x|x|^\alpha & ...
