User GPerez

27 votes

Is there a vector field that is equal to its own curl?

answered Jan 4, 2015 at 4:12

16 votes

Accepted

How to construct change of basis matrix

answered Jan 5, 2014 at 15:26

12 votes

Derivation of divergence in spherical coordinates from the divergence theorem

answered May 28, 2015 at 22:07

10 votes

Why is the composition of smooth multivariable functions smooth?

answered Apr 13, 2015 at 14:27

9 votes

Whats the difference between Antisymmetric and reflexive? (Set Theory/Discrete math)

answered Apr 27, 2015 at 18:25

9 votes

Accepted

Zero Partials imply Constant Function Theorem or Proof

answered Jan 7, 2015 at 23:27

8 votes

Is a function changed into another function by a change of variables?

answered Jan 5, 2015 at 15:30

7 votes

What is wrong with this putative proof?

answered Apr 2, 2015 at 20:58

7 votes

Accepted

Easy application of the Riemann Mapping Theorem

answered May 19, 2015 at 18:39

7 votes

Accepted

If $f:X \to [0,1]$ be an onto continuous map and $\{f^{-1} (y)\}$ is compact then Is $X$ compact?

answered May 19, 2015 at 16:45

6 votes

Accepted

Understanding the use of the Cartesian Product in the proof of $|\mathbb R\times \mathbb R|=|\mathbb R|$

answered May 12, 2015 at 23:04

6 votes

limit is also bounded if sequence is bounded and converge?

answered Dec 6, 2014 at 11:02

5 votes

Accepted

Using roots and exponents when solving inequalities

answered Jan 17, 2014 at 3:17

5 votes

Accepted

What is the difference between vector-valued functions and parametric equations?

answered Feb 3, 2014 at 13:51

5 votes

Accepted

System of equations involving sin and cos

answered May 11, 2015 at 20:14

4 votes

How to position negative sign of fraction

answered May 28, 2015 at 20:35

4 votes

Accepted

Integrating wrt to same parameter twice

answered Jun 15, 2015 at 6:59

4 votes

Accepted

Open or closed intervals?

answered Feb 3, 2014 at 15:32

4 votes

Mnemonic for cross product

answered Jan 15, 2014 at 20:02

4 votes

Example of contraction mapping

answered Feb 20, 2015 at 8:33

3 votes

Why if matrix $A$ is invertible and $A(\mathbf{x-y})=0$ then $\mathbf{x-y}=0$?

answered Jan 5, 2015 at 19:23

3 votes

How do I evaluate $\sum_{r=1}^{n} [r(r+1)(r+2)(r+3)] $?

answered Jan 3, 2015 at 14:57

3 votes

Is a function defined at a single point continuous?

answered Jan 8, 2015 at 0:01

3 votes

Accepted

The series $\sum_{n=1}^\infty \frac{\sin(n\pi/3)}{\sqrt{n+1}}$ converges/diverges?

answered Jan 4, 2015 at 17:08

3 votes

What is the difference between a point and a vector?

answered Jan 21, 2014 at 1:53

3 votes

Accepted

Induced norm question.

answered Jan 4, 2014 at 10:43

3 votes

$f_x(x,y)=f_y(x,y)$ for all $(x,y)\in\mathbb{R}^2 \iff f(x,y)=f(0,x+y)$

answered Jun 10, 2015 at 19:42

3 votes

Is there official notation to represent "perform an operation n times"?

answered May 25, 2015 at 23:45

3 votes

Accepted

Help setting out a proof about the circle $x^{2} + y^{2} + 2gx + 2fy + c = 0$

answered May 11, 2015 at 18:31

3 votes

If $ f'(c) > 0 $, then there is an $ x $ such that $ f(x) > f(c) $.

answered Apr 23, 2015 at 21:23

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123 Answers

Is there a vector field that is equal to its own curl?

How to construct change of basis matrix

Derivation of divergence in spherical coordinates from the divergence theorem

Why is the composition of smooth multivariable functions smooth?

Whats the difference between Antisymmetric and reflexive? (Set Theory/Discrete math)

Zero Partials imply Constant Function Theorem or Proof

Is a function changed into another function by a change of variables?

What is wrong with this putative proof?

Easy application of the Riemann Mapping Theorem

If $f:X \to [0,1]$ be an onto continuous map and $\{f^{-1} (y)\}$ is compact then Is $X$ compact?

Understanding the use of the Cartesian Product in the proof of $|\mathbb R\times \mathbb R|=|\mathbb R|$

limit is also bounded if sequence is bounded and converge?

Using roots and exponents when solving inequalities

What is the difference between vector-valued functions and parametric equations?

System of equations involving sin and cos

How to position negative sign of fraction

Integrating wrt to same parameter twice

Open or closed intervals?

Mnemonic for cross product

Example of contraction mapping

Why if matrix $A$ is invertible and $A(\mathbf{x-y})=0$ then $\mathbf{x-y}=0$?

How do I evaluate $\sum_{r=1}^{n} [r(r+1)(r+2)(r+3)] $?

Is a function defined at a single point continuous?

The series $\sum_{n=1}^\infty \frac{\sin(n\pi/3)}{\sqrt{n+1}}$ converges/diverges?

What is the difference between a point and a vector?

Induced norm question.

$f_x(x,y)=f_y(x,y)$ for all $(x,y)\in\mathbb{R}^2 \iff f(x,y)=f(0,x+y)$

Is there official notation to represent "perform an operation n times"?

Help setting out a proof about the circle $x^{2} + y^{2} + 2gx + 2fy + c = 0$

If $ f'(c) > 0 $, then there is an $ x $ such that $ f(x) > f(c) $.