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ys wong
  • Member for 8 years, 2 months
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11 votes
4 answers
23k views

Prove that trees have at least two vertices of degree one

7 votes
2 answers
5k views

Continuity of $\frac{2xy}{x^2+y^2}$ at $(0,0)$

6 votes
1 answer
3k views

Finding continuity and differentiability of a multivariate function

6 votes
2 answers
2k views

Finding the limits of a multivariable function $\frac{x^2y^2}{x^4+y^2}$

5 votes
2 answers
2k views

Do these two parametric equations represent the same curve?

5 votes
1 answer
2k views

Proving dimension formula in linear algebra

4 votes
2 answers
115 views

Determining the rank of the matrix (Linear algebra)

4 votes
1 answer
47 views

Finding the invertibility of a matrix (linear algebra)

4 votes
4 answers
215 views

Show that $\,\,\, \lim_{n\to\infty} \sin\bigl(\pi\sqrt{n^2+1}\bigr)=0 $

3 votes
5 answers
2k views

Multivariate limit $\lim_{(x,y) \to (0,0)} \frac{{x{y^2}}}{{{x^2} + {y^4}}} = 0$

3 votes
2 answers
636 views

Existences and uniqueness theorem, finding a unique solution of a first order ODE

3 votes
1 answer
4k views

Probability that 4 friends will be in the same class

3 votes
2 answers
94 views

Proving a property of a prime number (Elementary number theory)

3 votes
1 answer
2k views

Solving a second Order ODE of a catenary curve

3 votes
1 answer
59 views

Finding a system of linear equations (Linear Algebra)

3 votes
3 answers
6k views

Finding the probability of whether it would rain on weekends

3 votes
2 answers
172 views

Proving the converging of subsequences (Real Analysis)

3 votes
4 answers
3k views

Proving whether the difference of two series is convergent of divergent

3 votes
3 answers
108 views

Evaluate the following complex integrals using parameterisation $\int \limits_{\beta} f(z) dz$

3 votes
1 answer
541 views

Will Fermat's last theorem hold true on the Complex Plane? [duplicate]

2 votes
3 answers
1k views

Prove/Disprove that the set of rational numbers is uncountable (Real Analysis)

2 votes
0 answers
807 views

Solve the Neumann problem for the wave equation on the half line $-\infty < x <0 $.

2 votes
0 answers
340 views

Showing that the equation $f(x)=1$ satisfy the condition of the fourier integral

2 votes
4 answers
231 views

Calculate $5^{2016} \pmod 7$

2 votes
3 answers
739 views

Using the Well ordering Principal to prove a property of integers

2 votes
2 answers
101 views

Determining the span of the vector space (linear Algebra)

2 votes
4 answers
157 views

Proving the invertibility of an $n$ by $n$ matrix (Linear algebra)

2 votes
1 answer
780 views

Properties of the inverse of an upper triangular matrix

2 votes
1 answer
63 views

Proving the invertibility of matrices $AB$ and $BA$

2 votes
4 answers
4k views

Using the Existence and uniqueness theorem to find the interval of validity of a unique solution in a Linear ODE

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