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Apr
14
reviewed Reject Is there a symbol for always less than (or just always?)
Apr
14
reviewed Edit Convergence of a complex series for some values of z
Apr
14
revised Convergence of a complex series for some values of z
notation issues
Apr
14
reviewed Reject Problem with differential equation,someone to give hint?
Apr
14
reviewed Approve Is there a symbol for always less than (or just always?)
Apr
14
reviewed Edit Is there a symbol for always less than (or just always?)
Apr
14
revised Is there a symbol for always less than (or just always?)
formatting
Apr
13
answered Is this outer measure really regular?
Apr
13
comment Is this outer measure really regular?
What you have showed is that $\overline{\mathbb{S}}=\{\emptyset,X\}$. Does this violate outer-regularity?
Apr
13
comment Proving that a certain function is well-defined
For $T$ to be well defined you need to show that $Tf$ is a continuously differentiable function for any continuous $f$. I.e. $Tf\in C^1[0,1]$ for any $f\in C[0,1]$. But this is implied by the fundamental theorem of calculus as the answers below indicate.
Apr
11
answered How do I show the series $\sum{\frac{1}{\log(n)^{\log(n)}}}$ converges?
Apr
5
comment Prove that the vector space is 3D
@copper. Great! you're welcome.
Apr
5
comment Prove that the vector space is 3D
@copper. Look up the definition for dimension. The dimension of a vector space is defined as the number of linearly independent vectors that spans it.
Apr
5
comment Prove that the vector space is 3D
@copper if $ax+be^{x}+c\sin(x)=0$ in $C(\mathbb{R})$ means that $ax+be^{x}+c\sin(x)$ is equal to the function that is zero everywhere. So this equation holds for all $x\in\mathbb{R}$. Now you can go ahead and choose your favorite $x$ values and plug them in to conclude that we must have $a=b=c=0$. I gave you one choice of such $x$ but there are plenty of other options for this.
Apr
5
comment Prove that the vector space is 3D
@copper $span\{x,e^{x},\sin(x)\}=\{ax+be^{x}+c\sin(x):a,b,c\in\mathbb{R}\}=V$ by definition of span and $V$.
Apr
5
revised Prove that the vector space is 3D
added 343 characters in body
Apr
5
answered Prove that the vector space is 3D
Apr
5
reviewed Approve How can I prove that column space of $A^2$ contained in the column space of $A$?
Apr
3
reviewed Approve injective linear transformation basis.
Mar
29
reviewed Reject Determinant of a symmetric, sparse matrix