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gbox
  • Member for 10 years, 8 months
  • Last seen more than a week ago
28 votes
4 answers
23k views

Why is determinant a multilinear function?

19 votes
4 answers
21k views

When can I move the limit operand into a function?

17 votes
2 answers
56k views

Symmetric matrix multiplication

17 votes
5 answers
25k views

Are inverse matrices unique?

14 votes
3 answers
73k views

Prove: Square Matrix Can Be Written As A Sum Of A Symmetric And Skew-Symmetric Matrices

13 votes
3 answers
91k views

Finding the limit of $\frac{1-\cos x}{x^2}$

13 votes
4 answers
5k views

The whole space is an open set in a metric space

12 votes
2 answers
28k views

Proof of the derivative of $x^n$

10 votes
1 answer
6k views

Sufficient and necessary conditions for matrix to be diagonalize or triangular

8 votes
1 answer
2k views

Why in the proof of $A\cdot Adj(A)=Det(A)\cdot I_n$ entires not on the diagonal are zero?

8 votes
4 answers
6k views

Prove: if $f(0)=0$ and $f'(0)=0$ then $f''(0)\geq 0$

7 votes
4 answers
1k views

Evaluate the integral $\int^{\infty}_{0} e^{-x}x^{100}dx$

7 votes
6 answers
481 views

integrate $\int_0^{\frac{\pi}{4}}\frac{dx}{2+\tan x}$

7 votes
2 answers
127 views

Prove: $z^{12}+3z^8+101z^4+1$ has a root on the unit circle

7 votes
3 answers
590 views

Evaluate $\lim_{n \to \infty} \sqrt[n]{3^n+4^n}$ [duplicate]

6 votes
2 answers
1k views

Einstein Notation

6 votes
5 answers
904 views

Evaluate $\lim_{x\to 0}\frac{x-\sin x}{x\sin x}$ without to use L'Hopital

6 votes
4 answers
1k views

Prove: there is a point where the derivative is zero

6 votes
3 answers
672 views

Approximation of the Sine function near $0$

6 votes
2 answers
9k views

Multiplication of inverse and non-inverse matrices

5 votes
1 answer
3k views

$\dim C(AB)=\dim C(B)-\dim(\operatorname{Null}(A)\cap C(B))$

5 votes
1 answer
3k views

Are all fields vector spaces?

5 votes
4 answers
2k views

How can I Prove $\frac{2xy}{x+y}\leq \sqrt{xy}\leq \frac{x+y}{2}$

5 votes
1 answer
2k views

How much is ${\aleph_0}^{\aleph _ 0}$? [duplicate]

5 votes
1 answer
104 views

converge/divergence of a series with a n-th root

5 votes
1 answer
305 views

Prove a sequence converges using sub-sequences

5 votes
1 answer
559 views

Jordan normal form over $\mathbb{C}$

5 votes
2 answers
3k views

Why binomial distribution doesn't count permutations?

5 votes
2 answers
3k views

Proof: Antiderivative of a function differ by a constant

5 votes
3 answers
128 views

Evaluate $\int_{-1}^{1} \frac{x^3\,e^{\sin \left( \cos \left( x \right) \right)}+1}{x^2+1}\mathrm{d}x$

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