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Mike
  • Member for 12 years, 8 months
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27 votes
9 answers
21k views

Diophantine equation $a^2+b^2=c^2+d^2$

14 votes
5 answers
2k views

Another quadratic Diophantine equation: How do I proceed?

8 votes
3 answers
2k views

Pythagorean quadruples

8 votes
2 answers
423 views

Integral $-\int_{0}^{a}{at^{3}\,{\rm d}t\over\,\sqrt{\,\left(a^{2} -t^{2}\right)\left(b^{2}t^{2} +a^{4}-a^{2}t^{2}\right)\,}\,}$

7 votes
1 answer
3k views

Need refresher on z-transforms and difference equations

7 votes
2 answers
1k views

Divisibility of Fibonacci numbers

5 votes
4 answers
9k views

Volume of a surface of revolution with curve in parametric form

5 votes
3 answers
2k views

exponentiation and modular arithmetic

5 votes
3 answers
7k views

Solving quadratic Diophantine equations: $5n^2+2n+1=y^2$ [duplicate]

5 votes
1 answer
523 views

A summation involving the ceiling function

4 votes
2 answers
2k views

Factor groups and isomorphisms

4 votes
2 answers
371 views

rational triangles and cosines

3 votes
1 answer
86 views

$\gcd(x^2+1,x^2+4x+5)$

2 votes
2 answers
621 views

Question on reduction of order for linear ODEs

2 votes
2 answers
168 views

Need help interpreting a passage from an old text on Diophantine equations

2 votes
2 answers
115 views

Question on MIT video on Markov matrices

2 votes
3 answers
7k views

Is there a shortcut for calculating summations such as this? [duplicate]

2 votes
1 answer
414 views

An exponential recurrence

1 vote
1 answer
359 views

Trig integral 2 ways: are both equivalent?

1 vote
0 answers
385 views

Is this Diophantine equation proof correct?

1 vote
3 answers
247 views

Numbers of the form $x^2+axy+by^2$

1 vote
0 answers
39 views

Mistake involving Chinese remainder theorem

1 vote
2 answers
83 views

Does $\sum\limits_{k=5}^n\binom{k-3}2\binom{k-1}3$ have a closed form?

0 votes
0 answers
127 views

$\int\cos^a xdx$