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SFR
  • Member for 4 years, 2 months
  • Last seen more than a week ago
7 votes
5 answers
223 views

How to derive the polar equation of a circle.

4 votes
1 answer
2k views

I need an example of two non-isomorphic graphs with the same degree sequence.

3 votes
2 answers
61 views

Find the parametric equation of a line different from, yet parallel to $( x, y, z ) = (1, 1, -1) + t(1, -2, -1)$

3 votes
3 answers
1k views

When you're given a degree sequence, what is the method to draw a graph which has that degree sequence?

3 votes
3 answers
189 views

Let $G$ be the set of all functions $g : ℕ \to \{0,1\}$. Prove that $G$ is uncountable.

2 votes
2 answers
121 views

A question on counting

2 votes
2 answers
468 views

Number of paths of length $P_{n-1}$ in $K_n$?

1 vote
3 answers
48 views

I need help to determine the $\lim_{x\to0^-} \frac{x^2\sin(1/x)}{\sin(x)}$?

1 vote
2 answers
246 views

Let R be a ring in which $x^2=x$ for all x ε R. (a) Prove that $x + x = 0$ for for all x ε R. (b) Prove that R is commutative. [duplicate]

1 vote
3 answers
80 views

How to prove $\sum_{n=1}^{\infty} \frac{1}{\sqrt{n+1}+\sqrt{n}} $ diverges using the comparison test.

1 vote
1 answer
101 views

Pigeonhole principle Q: What is the smallest integer k with the following property: whenever x_1, ... ,x_k are integers between 1 and 15, either (i) …

1 vote
2 answers
690 views

A very simple question on motion in a circle.

1 vote
1 answer
35 views

I need help understanding a simple proof about determinants of matrices.

1 vote
1 answer
45 views

Write $m\ddot{x}$ = $-k(t)x$ as a dynamical system.

0 votes
1 answer
38 views

A question on multiplying cosets together.

0 votes
2 answers
63 views

Let $\theta : \mathbb{C} → \mathbb{R}$ be a homomorphism. Prove that $\theta(x) = 0$ for all $x \in \mathbb{C}$.

0 votes
3 answers
27 views

Proving that n = O (log(n)) is not true.

0 votes
2 answers
64 views

Rotating the conic $25x^2+25y^2-14xy-32\sqrt{2}x+32\sqrt{2}y-256=0$

0 votes
1 answer
26 views

Simple question on discrete random variable. 6 balls a drawn from a bag of balls numbered 1 to 49 with replacement.

0 votes
1 answer
225 views

Ignoring vertex labels, how many distinct trees are there with 5 vertices?

0 votes
3 answers
963 views

Let $F$ be the set of all functions $f : \{0,1\} \rightarrow \mathbb N$. Prove that $F$ is countable.

0 votes
3 answers
22 views

Give an example of a bijection from R to (0,1). A sketch graph that clearly indicates the key features of your example will suffice.

0 votes
0 answers
35 views

An easy question (given as an image) of showing $\ker θ = \langle X^2-1\rangle$ where $ θ : ℝ[X] \to M_2(ℝ)$ is a homomorphism.

0 votes
0 answers
50 views

A question (given as an image) on how to show a polynomial ring is equal to a principal ideal.

0 votes
1 answer
45 views

A question on counting and probability: Six friends hold a Christmas present swap. Each person brings a present, and puts it into a sack... [duplicate]

0 votes
3 answers
46 views

Simple mechanics problem.

-1 votes
2 answers
79 views

Does the series $\sum_{n=1}^{\infty} (-1)^{n+1}\sqrt{n} $ converge?

-1 votes
4 answers
35 views

Without using l’Hopital’s Rule, determine $\lim_{x\to\ 25} \frac{\sqrt x - 5}{x-25}$.