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peter.petrov
  • Member for 8 years, 5 months
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24 votes
Accepted

What is wrong with this argument that closed interval [0, 1] is not compact?

19 votes
Accepted

Normalizing a quaternion

13 votes
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If $ab=ba$, Prove $a^2$ commutes with $b^2$

12 votes

So what really is a random variable?

11 votes

What number follows immediately after a rational number?

9 votes
Accepted

Showing planarity of graphs

8 votes

How can a square root be defined since it has two answers?

8 votes

Solve the system of equations $x+2^x=y+2^y$ and $x^2+xy+y^2=12$

8 votes

Determining the closed form of $\sum\limits_{r = 2}^n \binom{n}{r} \binom{r}{2}$

7 votes

The number of real roots of $x^5 + 2x^3 + x^2 + 2 = 0 $ is

7 votes
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Difference between a limit and accumulation point?

7 votes
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How can I improve creative thinking in Math?

6 votes
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Proving equality - a sum including binomial coefficient $\sum_{k=1}^{n}k{n \choose k}2^{n-k}=n3^{n-1}$

6 votes
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Number of $60$th primitive roots of $-1$

6 votes

Will these frogs ever meet?

6 votes

Important Trigonometric Angles 's Values To Remember For IIT-JEE?

6 votes
Accepted

Show that $x^2+y^2 = 3$ has no rational solutions

5 votes

Spivak - Chapter 7 Question 5 - Could f(x) be a function other than a constant function?

5 votes
Accepted

$a \Rightarrow b$, $b \Rightarrow c$, $c \Rightarrow d$, $d \Rightarrow a$. Argue that any two of these statements are logically equivalent.

5 votes

prove $\max\{x,y\} = (x+y+|x - y|)/2$

5 votes
Accepted

Solve for $x$ for the following exponential equation $2^{2x+1} = 3^{2x+1}$. What am I doing wrong?

5 votes
Accepted

Cantor Set ternary representation

5 votes
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Explain how can we graph the equation $y+|y|=x+|x|$.( Relation involving absolute values)

5 votes
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How to use Pigeon Hole Principle here?

5 votes
Accepted

Solve the inequality $x^4-3x^2+5\ge0$

5 votes
Accepted

How to integrate $\int_{-\infty}^{\infty} xe^{-2\lambda |x|} dx$?

5 votes

Recurrence without intuitive leaps

5 votes
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Area of a Semi-Regular Decagon

4 votes
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Rewrite $x \notin A$ using negation proper way?

4 votes
Accepted

How to find the inverse of $f(x)=x+ \frac{x^{3}}{1+x^{2}}$?

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