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trombho
  • Member for 3 years
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7 votes
0 answers
145 views

Conjecture: There is no $n\neq3$ such that $\arctan(1)+\arctan(2)+\cdots+\arctan(n)=\frac{k\pi}{2}$, with $k$ integer.

5 votes
3 answers
158 views

Area triangle (possible)

5 votes
3 answers
360 views

Calculate the value of angle $ACB$

4 votes
1 answer
247 views

Midpoints, bisectors, orthocenter, incenter and circumcenter

4 votes
1 answer
347 views

Greatest prime divisor of $ n^2+1$

4 votes
2 answers
120 views

Number primes digits

3 votes
1 answer
312 views

Find all integers

3 votes
2 answers
56 views

Numeric combination

2 votes
2 answers
121 views

Travel Logic (mod. 4)

2 votes
1 answer
123 views

Mansion point and incenter

2 votes
1 answer
101 views

Inequality with 5 cyclic variables

2 votes
1 answer
206 views

$99 \times 99$ colored square grid

2 votes
2 answers
77 views

Showing that successive arches of $y=e^{-\alpha x}\sin\beta x$ bound areas in geometric progression with ratio $q=e^{-\alpha\pi/\beta}$

2 votes
2 answers
301 views

Pairs of perfect squares

2 votes
1 answer
45 views

Calculate the optimal ratio AX/AB

2 votes
2 answers
624 views

Cubic diophantine equation with a prime $x^3 + y^3 + z^3 - 3xyz = p$.

2 votes
3 answers
108 views

Numerical bases and prime number theory

2 votes
1 answer
56 views

Prime Number Theory (Dividers)

2 votes
0 answers
40 views

Numbering system [closed]

2 votes
2 answers
86 views

Prove that $a = b$ [duplicate]

2 votes
2 answers
187 views

Numeric sequence [duplicate]

2 votes
1 answer
108 views

Solve the equation $x! + y!+z!= 2^{v!}$

2 votes
1 answer
72 views

Square and rectangle

2 votes
2 answers
209 views

Determine all pairs $(a, b)$ for which $s (an + b) - s (n)$ assumes finitely many values

2 votes
0 answers
69 views

Verification of my solution of the functional equation $ f \left( x + y ^ 2 \right) = f ( x ) +f ( y ) ^ 2 $

2 votes
0 answers
62 views

Matching scientists and topics with certain restrictions

2 votes
1 answer
109 views

Expected Value with RNG

2 votes
1 answer
53 views

Find a formula for $\int ^x _0 [t] \,dt$, $x>0$ real.

2 votes
1 answer
283 views

How many angles have integer measure in degrees and are interior angles of an integer-sided triangle?

1 vote
3 answers
66 views

Determine the value of $\sum_{i=1}^{2019}\frac{x_i}{x_i-1}$