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User8128
  • Member for 8 years, 3 months
  • Last seen this week
20 votes
Accepted

Inverse of a symmetric positive definite matrix

16 votes

Prove that a symmetric matrix with a positive diagonal entry has at least one positive eigenvalue

16 votes

The Hahn-Banach Theorem for Hilbert Space

12 votes

Find a bijection from $[0,1]$ to $[0,1]$ that is not strictly monotone. is this possible?

11 votes

$y=\frac{(e^x - e^{-x})}{2}$. Solve for x

11 votes
Accepted

$ L ^ 2 $ norm of a function and its derivative

11 votes
Accepted

Show that sup $f_n$ and inf $f_n$ are measurable if {$f_n$} is a sequence of measurable functions

10 votes
Accepted

poincaré inequality direct proof

10 votes
Accepted

Determine the eigenvalue of a real matrix

9 votes
Accepted

Well definition of newtonian potential

9 votes
Accepted

Differential Equation with y(-x)

9 votes

Disagreement with professor about Cauchy Sequence

8 votes
Accepted

All norms of $\mathbb R^n$ are equivalent

8 votes
Accepted

express $\sum_{n=1}^{\infty}\frac{nx^n}{(n+1)!}$ as elementary functions

8 votes

Prove that if $|f(x)| \leq x^2$, then the function is continuous and differentiable at $x=0$.

8 votes

Solve integral $\int_1^2x\,d[x^2]$ with floor differential.

7 votes
Accepted

How to describe a summation of $\frac{1}{2^x3^y}$ and evaluate.

7 votes

How to evaluate the following integral: $\int_0^1\frac{\log(1+x)}{1+x^2}dx$

7 votes

Convergence of $\sum2^{-\sqrt{k}} $

7 votes
Accepted

Convergence in $L^p$ and convergence almost everywhere

7 votes

Alternate proof of the dominated convergence theorem by applying Fatou's lemma to $2g - |f_n - f|$?

7 votes
Accepted

A Lebesgue integrable function whose absolute value is not Lebesgue integrable

7 votes

Series that evaluates to different values

7 votes

Does continuity depend on the distance function?

6 votes

Solve PDE $u_{t} = u_{xx} + u$

6 votes

Dimension of range space of the linear operator $T: C[0, 1]\to C[0, 1]$

6 votes
Accepted

Evaluate the indefinite integral of multiplication of two functions

6 votes
Accepted

How do I prove the inequality $(\sum a^3)^2 \leq (\sum a^2)^3$?

6 votes
Accepted

Showing that $M := \{f \in C([-1,1]) : f(0) > 0\}$ is open

6 votes
Accepted

How can I prove analytically that the golden ratio is less then $\frac{\pi^2}{6}$.

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