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gandalf61
  • Member for 5 years, 3 months
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33 votes
Accepted

Is it possible to shorten the solution for this 2014 RMO question?

21 votes
Accepted

What is the probability that the first head will appear on the even numbered tosses

16 votes
Accepted

Need Help : Proving polynomials are continuous, without circular reasoning

15 votes

Find $\prod^\infty_{n=1} (1 - 10^{-3* 2^n})$.

14 votes
Accepted

Is there a name for categories whose objects are sets?

11 votes

Degree of the eighth vertex given the other degrees

11 votes

A quick way, say in a minute, to deduce whether $1037$ is a prime number

10 votes

Say $a=b$. Is "Do the same thing to both sides of an equation, and it still holds" an axiom?

10 votes
Accepted

Can the inverse of this function be expressed in closed form?

10 votes
Accepted

After deleting the multiples of $2$ and multiples of $3$ from list of integers from $1$ to $N$, why are a fifth of the numbers still multiples of 5?

10 votes

How is the similarity of the structure of two functions defined?

10 votes

What are the possible values of these letters?

9 votes

What is the difference between complex numbers and 2D vectors?

9 votes

Where are the imaginary numbers in Fourier analysis hiding?

9 votes
Accepted

Question on speed.

9 votes

Why is it important for a matrix to be square?

8 votes
Accepted

What does it mean for something to be a model of hyperbolic space?

8 votes
Accepted

Find the limit of sequence $\frac{1}{2}+\frac{3}{2^{2}}+\frac{5}{2^{3}}+\cdots+\frac{2n-1}{2^{n}}$ without using of derivatives and etc.

8 votes

How would antique math books compare to modern books?

8 votes

Can we say that an element is not a subset of a set?

8 votes

Limit of a sequence of integrals involving continued fractions

7 votes

Unexplained log simplification, can someone show how?

7 votes

Number of positive real roots in equation $x^6 - x - 1 =0$

7 votes

How is $0$ generated from $1$ or $-1$?

7 votes

Let k be an integer. Disprove: “The equation $x^2 − x − k = 0$ has no integer solution if and only if $k$ is odd.”

6 votes

Without using a calculator can you say, which number is greater, $65^{1662}$ or $33^{1995}$?

6 votes

What's the intuition behind the fact that you can factorise an expression as $(x-a)(x-b)$ if $a$ and $b$ are the roots of the expression

6 votes

Prove all derivatives of $f(x)=\frac{1}{1+x}$ by induction

5 votes
Accepted

Calculate the value of $\frac{1}{2}+\frac{1}{4}+\frac{2}{8}+\frac{3}{16}+....+\frac{F_n}{2^n}+....$

5 votes

What is the number of pairs of $(a,b)$ of positive real numbers satisfying $a^4+b^4<1$ and $a^2+b^2>1$?

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