User Sean Lee

6 votes

Accepted

Prove $\mathrm{tr}(A^2) \leq\mathrm{tr}(A^TA)$

answered Apr 5, 2019 at 11:00

4 votes

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Probability of rolling first 3 with a fair die before 10th roll and after 4th roll.

answered Jan 24, 2019 at 3:03

3 votes

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Point $x \in \mathbb{R}^n$ that minimizes sum of distance squares $\sum_{\mathcal{l}=1}^{k} \Vert x-a^{\mathcal{(l)}} \Vert _2^2$

answered Nov 30, 2018 at 12:08

3 votes

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Computing the expectation of the number of balls in a box

answered Apr 11, 2019 at 18:01

3 votes

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Showing an Inequality Holds True

answered Mar 6, 2019 at 5:16

3 votes

How can I define an infinitely small positive value?

answered Mar 6, 2019 at 4:33

3 votes

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How many people have to be in a group so that the probability of at least one of them is left-handed is 0.9?

answered Apr 3, 2019 at 16:44

2 votes

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Given a coin's bias, how can two flips be conditionally independent?

answered Jan 1, 2022 at 5:18

2 votes

how to make the objective value of primal program close to zero

answered Feb 27, 2022 at 5:36

2 votes

Looking for intriguing applications of martingales

answered Mar 27, 2019 at 11:51

2 votes

$\sum_{n=1}^\infty a_n^{b_n}$ converges

answered Nov 29, 2018 at 1:57

1 vote

find a general formula for $E(X^t)$ when X has the log-normal distribution

answered Nov 29, 2018 at 2:38

1 vote

Accepted

Find the extrema and saddle points of $f (x,y)=e^x \sin(y)$

answered Dec 3, 2018 at 16:03

1 vote

Probability of objects are being sorted

answered Dec 3, 2018 at 18:06

1 vote

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Calculate average/probability of an action happening in a shrinking pool

answered Jan 25, 2019 at 1:03

1 vote

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Transforming conditional probability

answered Jan 26, 2019 at 19:28

1 vote

Formal evidence for statement involving matrices A and AB times vector x = c

answered Feb 2, 2019 at 14:24

1 vote

Geometric Interpretation of "$A,B\subseteq \mathbb{C}$, there exists a point $a∈A$ such that $∀x∈A,y∈B $ there exists $b∈B$ such that $|a−b|≤|x−y|.$

answered Feb 17, 2019 at 18:19

1 vote

Derivation of the trace with Hessian matrix

answered Nov 29, 2018 at 19:41

1 vote

Accepted

Proving an algebraic binomial identity related to Bertrand's ballot theorem

answered Apr 8, 2019 at 21:41

1 vote

Accepted

Polar co-ordinates, Jordan form, Axler textbook

answered Apr 11, 2019 at 22:37

1 vote

Accepted

How does jointly Gaussian random variables relate to Gaussian random variables?

answered Mar 6, 2019 at 5:02

1 vote

Accepted

Question on mixed-strategy matrix games from Boyd & Vandenberghe

answered Mar 21, 2019 at 9:42

1 vote

Fewest number of marbles in a bag such that drawing the probability of drawing 2 blue marbles is $\frac{1}{6}$.

answered Mar 22, 2019 at 2:26

1 vote

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20 people 20 files in a meeting

answered Mar 25, 2019 at 13:33

1 vote

Accepted

If using a 3 sided dice, what is the probability of landing on a 1 exactly 3 times and on a 2 exactly two time?

answered Mar 8, 2019 at 3:25

1 vote

About formula of probabilities of entire sequences

answered Apr 11, 2019 at 14:17

1 vote

Accepted

How to evaluate $\lim_{n\to\infty}k^{\frac{1}{n}}$ using the Sandwich theorem?

answered Aug 24, 2019 at 7:30

1 vote

Accepted

Expected value of sock pairs from k choices

answered Sep 26, 2019 at 15:14

1 vote

If A is an n×n invertible symmetric matrix, then (A^(-1) )^k is symmetric, for any positive integer k.

answered Mar 26, 2021 at 14:45

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42 Answers

Prove $\mathrm{tr}(A^2) \leq\mathrm{tr}(A^TA)$

Probability of rolling first 3 with a fair die before 10th roll and after 4th roll.

Point $x \in \mathbb{R}^n$ that minimizes sum of distance squares $\sum_{\mathcal{l}=1}^{k} \Vert x-a^{\mathcal{(l)}} \Vert _2^2$

Computing the expectation of the number of balls in a box

Showing an Inequality Holds True

How can I define an infinitely small positive value?

How many people have to be in a group so that the probability of at least one of them is left-handed is 0.9?

Given a coin's bias, how can two flips be conditionally independent?

how to make the objective value of primal program close to zero

Looking for intriguing applications of martingales

$\sum_{n=1}^\infty a_n^{b_n}$ converges

find a general formula for $E(X^t)$ when X has the log-normal distribution

Find the extrema and saddle points of $f (x,y)=e^x \sin(y)$

Probability of objects are being sorted

Calculate average/probability of an action happening in a shrinking pool

Transforming conditional probability

Formal evidence for statement involving matrices A and AB times vector x = c

Geometric Interpretation of "$A,B\subseteq \mathbb{C}$, there exists a point $a∈A$ such that $∀x∈A,y∈B $ there exists $b∈B$ such that $|a−b|≤|x−y|.$

Derivation of the trace with Hessian matrix

Proving an algebraic binomial identity related to Bertrand's ballot theorem

Polar co-ordinates, Jordan form, Axler textbook

How does jointly Gaussian random variables relate to Gaussian random variables?

Question on mixed-strategy matrix games from Boyd & Vandenberghe

Fewest number of marbles in a bag such that drawing the probability of drawing 2 blue marbles is $\frac{1}{6}$.

20 people 20 files in a meeting

If using a 3 sided dice, what is the probability of landing on a 1 exactly 3 times and on a 2 exactly two time?

About formula of probabilities of entire sequences

How to evaluate $\lim_{n\to\infty}k^{\frac{1}{n}}$ using the Sandwich theorem?

Expected value of sock pairs from k choices

If A is an n×n invertible symmetric matrix, then (A^(-1) )^k is symmetric, for any positive integer k.