Christian Blatter
Reputation
399/400 score
3 64 196
Impact
~2.0m people reached

• 4 helpful flags
• 3,538 votes cast

# 7,806 Actions

 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