Stack Exchange

Hans Lundmark

Linköping, Sweden

http://users.mai.liu.se/hanlu09/

top accounts reputation activity subscriptions
Top Questions
Top Answers
380
The Basel problem
math.stackexchange.com

185
How do I get the square root of a complex number?
math.stackexchange.com

121
Derivative of sigmoid function $\sigma (x) = \frac{1}{1+e^{-x}}$
math.stackexchange.com

116
An Introduction to Tensors
math.stackexchange.com

87
How can we sum up $\sin$ and $\cos$ series when the angles are in arithmetic progression?
math.stackexchange.com

79
Funny identities
math.stackexchange.com

71
What does E mean in 9.0122222900391E-5?
math.stackexchange.com

67
The Basel problem
math.stackexchange.com

59
lim sup and lim inf of sequence of sets.
math.stackexchange.com

56
Why do different calculators disagree on $\cos(452175521116192774 )$?
math.stackexchange.com

55
Why does a distance and its square reach their minimum at the same point?
math.stackexchange.com

47
How to make sense of fractions?
math.stackexchange.com

42
what does ∇ (upside down triangle) symbol mean in this problem
math.stackexchange.com

36
3rd type of vector multiplication beside dot/cross product?
math.stackexchange.com

36
What is limit of $\sum \limits_{n=0}^{\infty}\frac{1}{(2n)!} $?
math.stackexchange.com

36
Why is the matrix product of 2 orthogonal matrices also an orthogonal matrix?
math.stackexchange.com

34
For which number does multiplying it by 99 add a 1 to each end of its decimal representation?
math.stackexchange.com

32
Lesser-known integration tricks
math.stackexchange.com

32
Intuition of Gronwall lemma
math.stackexchange.com

31
Showing that the exponential expression $e^x (x-1) + 1$ is positive
math.stackexchange.com

29
What are affine spaces for?
math.stackexchange.com

28
What does limit notation with an underline or an overline mean?
math.stackexchange.com

28
What kind of "symmetry" is the symmetric group about?
math.stackexchange.com

26
Is the Lyapunov stability definition ambiguous?
math.stackexchange.com

26
Evaluating the integral $\int_0^\infty \frac{\sin x} x \,\mathrm dx = \frac \pi 2$?
math.stackexchange.com

26
How to intuitively understand parallel transport
math.stackexchange.com

24
Nice expression for minimum of three variables?
math.stackexchange.com

23
tough integral involving $\sin(x^2)$ and $\sinh^2 (x)$
math.stackexchange.com

22
In written mathematics, is $f(x)$a function or a number?
math.stackexchange.com

21
Lesser-known integration tricks
math.stackexchange.com

1 2 3 4 5 … 9