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Apr
22
answered arithmetic problem concerning equilateral triangle
Apr
21
revised Complex functions are continuous and differential when their real and imaginary components are continuous and differentiable
added 52 characters in body
Apr
21
answered Chain rule for second partial derivative of two different variables
Apr
21
answered Complex functions are continuous and differential when their real and imaginary components are continuous and differentiable
Apr
21
comment $f(|z|)$ is not an analytic function
I'm not assuming that $f$ is differentiable a priori. But if $g$ is holomorphic and $g(x)=f(x)$ for $x>0$ then $f$ has to be differentiable as a function of $x\in{\mathbb R}$.
Apr
21
revised Why is the magnitude of the curl of a vectorfield twice the angular velocity?
added 263 characters in body
Apr
21
answered Finding the surface area of $S={(r\cos\theta,r\sin\theta,3−r):0\leq r \leq 3, 0\leq \theta\leq2 \pi }$
Apr
21
answered Why is the magnitude of the curl of a vectorfield twice the angular velocity?
Apr
21
answered Intuitive proof for a Combinatorial Problem
Apr
21
answered $f(|z|)$ is not an analytic function
Apr
20
revised Numerical partial derivative of an inverse function
added 589 characters in body
Apr
20
comment Recursively defining the set of bit strings set having more zeros than ones
@Ludolila: 1) In (ii) it is assumed that $x\>y\in L$. If $x=y=\oslash$ this is not satisfied. 2) Start with $\oslash\>0=0\in L$ and produce successively $100=\oslash\>10\>0\in L$, $11000=1\>10\>00\in L$, etc.
Apr
20
answered Numerical partial derivative of an inverse function
Apr
19
comment Problem with basic definition of a tangent line.
@S.G.: Fine. What is your your idea what a "tangent" to a curve $\gamma$ at a point $P\in\gamma$ is?
Apr
19
comment Problem with basic definition of a tangent line.
@JohnDouma: My answer tries to convey a calculus-free idea of what a tangent line is. I'm describing under what circumstances the line $y=0$ could be called a tangent to a curve passing through $(0,0)$.
Apr
19
answered Equilateral Triangle Packing Problem
Apr
19
revised How the functions in a dual space look like?
added 12 characters in body
Apr
19
revised Problem with basic definition of a tangent line.
added 7 characters in body
Apr
18
comment Scissor equivalence/congruence of two convex hulls
I'm using the graphics program "Canvas" since 1995 or so.
Apr
18
revised How the functions in a dual space look like?
deleted 56 characters in body