User NNOX Apps

31 votes

2 answers

6k views

Strategies and Tips: What to do when stuck on math?

soft-question advice

asked Aug 6, 2013 at 10:34

24 votes

3 answers

2k views

How to Garner Mathematical Intuition

asked Aug 4, 2013 at 15:48

17 votes

4 answers

2k views

How can I correct my wrong Intuition that $\forall \, x \, \in \,\emptyset : P(x) \quad $ is false?

logic

asked Aug 28, 2013 at 9:04

17 votes

3 answers

21k views

If every convergent subsequence converges to $a$, then so does the original bounded sequence (Abbott p 58 q2.5.4 and q2.5.3b)

real-analysis proof-verification

asked May 1, 2014 at 11:20

15 votes

4 answers

31k views

Intuition for cross product of vector with itself and vector with zero vector

linear-algebra

asked May 10, 2013 at 23:19

13 votes

2 answers

14k views

Find all proper nontrivial subgroups of $\mathbb Z_2 \times \mathbb Z_2 \times \mathbb Z_2$ - Fraleigh p. 110 Exercise 11.10

group-theory solution-verification cyclic-groups

asked Jan 19, 2014 at 8:24

12 votes

3 answers

3k views

How can I prove $\nabla \cdot \color{green}{(\mathbf{F} {\times} \mathbf{G})} $ with Einstein Summation Notation?

multivariable-calculus derivatives

asked Jul 2, 2013 at 12:00

12 votes

1 answer

583 views

Journals or Magazines on Study Skills or How to Study Math

reference-request soft-question education self-learning

asked Jul 17, 2013 at 10:14

11 votes

4 answers

9k views

Equation of Cone vs Elliptic Paraboloid

geometry multivariable-calculus

asked May 7, 2013 at 21:58

11 votes

8 answers

10k views

Quotient Group G/G = {identity}?

group-theory

asked Dec 28, 2012 at 21:02

11 votes

4 answers

1k views

Scratch work for delta-epsilon proof for $\lim_{x \to 13} \sqrt{x-4} = 3$

real-analysis proof-verification

asked Feb 14, 2014 at 17:22

10 votes

1 answer

1k views

How often should math students take day breaks and longer breaks or vacations? Any research?

soft-question education advice

asked Jan 22, 2014 at 5:53

10 votes

3 answers

11k views

Tricks - Prove Homomorphism Maps Identity to Identity - Fraleigh p. 128 Theorem 13.12(1.)

group-theory intuition

asked Jan 22, 2014 at 16:55

10 votes

4 answers

1k views

Group Action - Permutation on the Polynomial

group-theory permutations symmetric-groups group-actions

asked Dec 24, 2012 at 21:37

10 votes

1 answer

10k views

Jacobian or No Jacobian - Surface Integrals

multivariable-calculus

asked May 10, 2013 at 18:07

9 votes

3 answers

10k views

Strong Induction Proof: Fibonacci number even if and only if 3 divides index

elementary-number-theory induction fibonacci-numbers proof-verification

asked Sep 9, 2013 at 15:14

8 votes

5 answers

8k views

Expression of an Integer as a Power of 2 and an Odd Number (Chartrand Ex 5.4.2[a])

elementary-number-theory

asked Sep 7, 2013 at 10:07

8 votes

2 answers

15k views

Which are the Bound and Free Variables in these expressions?

logic

asked Aug 24, 2013 at 8:29

8 votes

6 answers

2k views

How can I deduce a lower hemisphere's boundary's orientation?

multivariable-calculus

asked May 12, 2013 at 15:15

8 votes

3 answers

10k views

Combinatorial Proof of Multinomial Theorem - Without Induction or Binomial Theorem

combinatorics alternative-proof combinatorial-proofs

asked Nov 16, 2013 at 7:10

7 votes

6 answers

2k views

$ \{x : P(x)\} $ vs. $ \{P(x) : x\} $ ---- When are these set-builder notations the same and different?

elementary-set-theory intuition

asked Jul 12, 2013 at 8:40

7 votes

2 answers

2k views

Find all subgroups of $\mathbb{Z_2} \times \mathbb{Z_2} \times \mathbb{Z_4}$ isomorphic to the Klein $4$-group.

group-theory solution-verification cyclic-groups

asked Jan 19, 2014 at 14:47

7 votes

3 answers

10k views

A subsequence of a convergent sequence converges to the same limit. Questions on proof. (Abbott p 57 2.5.1)

real-analysis proof-verification

asked May 1, 2014 at 10:42

7 votes

1 answer

14k views

Determinant with Levi-Civita Symbol?

determinant

asked May 30, 2014 at 19:22

7 votes

1 answer

203 views

Explain to a 15 y.o. Byron Schmuland's answer that uses Summation and Product notations to solve the Crazy Lady Airplane Seat probability problem?

probability

asked Aug 23, 2021 at 8:58

6 votes

3 answers

703 views

How can a Fields Medallist be 'not very good at logic'? [closed]

logic education

asked Jan 27, 2017 at 16:09

6 votes

1 answer

22k views

What's the proof stategy for: Hermitian matrix has orthogonal eigenvectors for distinct eigenvalues?

linear-algebra matrices

asked Apr 21, 2014 at 13:53

6 votes

2 answers

264 views

Prove $ \int_{C}fdr=\int_{S}dS\times\nabla f$

multivariable-calculus

asked Mar 6, 2014 at 6:38

6 votes

2 answers

6k views

Intuition - If $Ax = b$ has infinitely many solutions, why can't $Ax = c$ have only one solution? [Strang P165 3.4. 22]

linear-algebra intuition

asked Jan 12, 2014 at 10:55

6 votes

1 answer

3k views

De-mystifying tricks in proof – If $\{x_n\}$ converges, then Cesaro Mean converges.

real-analysis sequences-and-series solution-verification

asked Feb 16, 2014 at 18:01

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444 Questions

Strategies and Tips: What to do when stuck on math?

How to Garner Mathematical Intuition

How can I correct my wrong Intuition that $\forall \, x \, \in \,\emptyset : P(x) \quad $ is false?

If every convergent subsequence converges to $a$, then so does the original bounded sequence (Abbott p 58 q2.5.4 and q2.5.3b)

Intuition for cross product of vector with itself and vector with zero vector

Find all proper nontrivial subgroups of $\mathbb Z_2 \times \mathbb Z_2 \times \mathbb Z_2$ - Fraleigh p. 110 Exercise 11.10

How can I prove $\nabla \cdot \color{green}{(\mathbf{F} {\times} \mathbf{G})} $ with Einstein Summation Notation?

Journals or Magazines on Study Skills or How to Study Math

Equation of Cone vs Elliptic Paraboloid

Quotient Group G/G = {identity}?

Scratch work for delta-epsilon proof for $\lim_{x \to 13} \sqrt{x-4} = 3$

How often should math students take day breaks and longer breaks or vacations? Any research?

Tricks - Prove Homomorphism Maps Identity to Identity - Fraleigh p. 128 Theorem 13.12(1.)

Group Action - Permutation on the Polynomial

Jacobian or No Jacobian - Surface Integrals

Strong Induction Proof: Fibonacci number even if and only if 3 divides index

Expression of an Integer as a Power of 2 and an Odd Number (Chartrand Ex 5.4.2[a])

Which are the Bound and Free Variables in these expressions?

How can I deduce a lower hemisphere's boundary's orientation?

Combinatorial Proof of Multinomial Theorem - Without Induction or Binomial Theorem

$ \{x : P(x)\} $ vs. $ \{P(x) : x\} $ ---- When are these set-builder notations the same and different?

Find all subgroups of $\mathbb{Z_2} \times \mathbb{Z_2} \times \mathbb{Z_4}$ isomorphic to the Klein $4$-group.

A subsequence of a convergent sequence converges to the same limit. Questions on proof. (Abbott p 57 2.5.1)

Determinant with Levi-Civita Symbol?

Explain to a 15 y.o. Byron Schmuland's answer that uses Summation and Product notations to solve the Crazy Lady Airplane Seat probability problem?

How can a Fields Medallist be 'not very good at logic'? [closed]

What's the proof stategy for: Hermitian matrix has orthogonal eigenvectors for distinct eigenvalues?

Prove $ \int_{C}fdr=\int_{S}dS\times\nabla f$

Intuition - If $Ax = b$ has infinitely many solutions, why can't $Ax = c$ have only one solution? [Strang P165 3.4. 22]

De-mystifying tricks in proof – If $\{x_n\}$ converges, then Cesaro Mean converges.