Jan Eerland's user avatar
Jan Eerland's user avatar
Jan Eerland's user avatar
Jan Eerland
  • Member for 7 years, 8 months
  • Last seen this week
  • The Netherlands
54 votes

How do you calculate $ 2^{2^{2^{2^{2}}}} $?

22 votes
Accepted

Hard integral to find

15 votes
Accepted

Compute $\int\limits_0^1 \log (2\arctan x+\frac{2x}{1+x^2})(1+x\arctan x)\ dx$

15 votes

Angle between the hour and minute hands at 6:05

12 votes
Accepted

Proving $\pi=(27S-36)/(8\sqrt{3})$, where $S=\sum_{n=0}^\infty\frac{\left(\left\lfloor\frac{n}{2}\right\rfloor!\right)^2}{n!}$

12 votes
Accepted

When $\cosh (z)=0$?

12 votes

How can I prove that $2^{2^x}+1$ is always prime?

11 votes
Accepted

Finding a closed form for an integral

11 votes

How to find length of a part of a curve?

11 votes
Accepted

Using only the ratio test....

11 votes
Accepted

How to prove that the following system of equations has only one solution?

11 votes
Accepted

Need help with Differential equation concept

10 votes
Accepted

Find a closed form for the following integral:

10 votes

$\int_0^1\int_0^1\binom{\text{something}}{\text{something}}\binom{\text{something}}{\text{something}}\cdot \text{something }dxdy$ with closed-form

10 votes

Why does $\sqrt{8^2+(8\sqrt 3)^2}=16$

10 votes
Accepted

Why $\frac{\pi}{12}$ equals to $\frac{\pi}{3} - \frac{\pi}{4}$

9 votes
Accepted

Fourier Series of $e^x$

8 votes

Why do I get a math error for this when trying to compute $\int_{-1}^1(x^2-\frac{1}{x^2}+3) \, dx$?

8 votes
Accepted

Evaluating $\int \frac{1-7\cos^2x}{\sin^7x\cos^2x}dx$

8 votes

Obtain magnitude of square-rooted complex number

8 votes

If $3x^2 -2x+7=0$ then $\left(x-\frac{1}{3}\right)^2 =$?

8 votes
Accepted

Solve for $c$ given $\frac{18}{2c}=3.8$

7 votes
Accepted

Find the closed-form solution to a integral with the floor function

7 votes
Accepted

What is this integral $\int {\sqrt{\frac{x+1}{x}}}\:dx$?

7 votes

Can the cosine function be written in "simpler" expressions?

7 votes
Accepted

Solve the equation: $\cos^2(x)+\cos^2(2x)+\cos^2(3x)=1$

7 votes

How can I solve $y''=\frac{a}{y^2}$ where a is a (positive) constant?

7 votes
Accepted

How to integrate $\sin (x^2)$ function?

7 votes

Limit evaluation for oscillating function

7 votes

Solving the following trigonometric equation: $\sin x + \cos x = \frac{1}{3} $

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