Recent content by juaninf

thanks by your attention, but, a important part is: In the preliminaries section, the item c), there a proposition that say: "So by our choice of g we get " [tex]\theta/p | \psi/p[\tex], how i use "So by our choice of g we get", Why g havenot any degree?, why choice small as posible that...

Hi every one In the preliminaries section, the item c), there a proposition that say: "So by our choice of g we get "\theta/p | \psi/p" whence "\theta | \psi" ". I am not understanding this propositión, Please help me ...

Let G group and N subgroup normal from G if b \in{G} and p is prime number then (Nb)^p=Nb^p, Please help me with steps to this proof.

is product of iterations (u^{n+1})*(u^n)

product \dfrac{u^{n+1} - u^{n}}{\vartriangle t} = (u^{n+1}u^n) this numerical method is from u'(t)=u^2

Please anyone help me with stability proof this next numerical method \dfrac{u^{n+1} - u^{n}}{\vartriangle t} = (u^{n+1}u^n)I am trying make : \begin{equation*} \begin{split} u_2^{n+1} - u_1^{n+1} & = \displaystyle\frac{u_2^{n}}{1-\vartriangle tu_2^{n}} -...

I maked this

yes, first left after right, i want only idea,

Supposse that y \in{R(T)}, T\in{L(V,W)} the equation Tx=y, have unique solution if only and if T is injectiva

Help for prove this please Let T\in{L(V,W)} The equation Tx=y have one solution iff y\in{R(T)}

Thank,I am reading this web http://www.voofie.com/content/152/how-to-prove-eat-e-at_0-eat-t_0/ but i don't understand how change sumatoria infinite to finite, Where i can read this?

fix question my question is How prove this, \exp(At)\exp(-At_0)=\exp(A(t-t_0)) using as above properties

How can prove this \exp(At)\exp(-At_0)=\exp(A(t-t_0))? using \displaystyle\sum_{i=0}^n{(1/k!)A^kt^k} and this properties in t=0 [\exp(At)]_{t} = I exp(At)exp(-At)=I \frac{dexp(At)}{dt}=Aexp(At)=exp(At)A

Understand but, In first prove (T* is invertivel) but how sure that <T*(T-1)*x,y> = <x,y> , if i don't know that (TT-1) is I, because is just that want will prove

then how is?