Recent content by Fallen Angel

Hi IssacNewton, Yes, the proof is correct.

Yes, that's correct.

Hi mathmari, There is no need of $f$ to be onto to prove $Im(gf)\subseteq Im(g)$ since, by definition, $f(z)\in C$

No, it isn't corect because you are assuming that And this isn't true. In my example above you can see that the unique maximal ideal is exactly the set of non-units of the ring $\mathbb{Z}_{(3)}$.

Hi, Is still false. Think on $\mathbb{Z}_{(3)}$, which is the localization of $\mathbb{Z}$ at the ideal $(3)$. Then $\mathbb{Z}_{(3)}=\{\dfrac{a}{b} \in \mathbb{Q} \ : \ 3\nmid b\}$. This ring has a unique maximal ideal $\mathfrak{m}=\{\dfrac{a}{b}\in \mathbb{Q} \ : \ 3\nmid b, \ 3 \mid a\}$...

Hi Peter, 1) It means that the sum is the minimal subspace that contains all its summands, i. e., it is contained in any other subspace containing that summands. About 2), a vector $v$ in $S+T$ can be written as $v=s+t$ with $s\in S, t\in T$. If i have a subspace containing $S$ and $T$, say...

Hi Peter, In the proof, we are assuming that $Y$ is linearly independent, so it can't contain null vectors. Once you have noted that $y_{1}\in Span(X)$ you hav that $y_{1}=\displaystyle\sum_{i=0}^{m}c_{i}x_{i}$ for some $c_{i}\in K$ (being $K$ the field under your vector space $V$). Now...

Oh sorry, I mixed up what was going on.Instead of %8i you should write %s since yearNumber is not an integer, is a string. (So you want to wirte things like Number: Junior ?:confused:) Anyhow I don't know why you have 10 sentences instead of 5, I don't have Malab right now so I can't run the...

Well, I think our code now fits quite good what the exercise says but, if you want to put some text on it, I would do the following. Inside the for loop and instead of the disp sentence you can write fprintf('\n Number: %8i\n', yearNumber) frpintf do more or less the same than disp, but have...

Hi, It seems that there is no compilation error (I didn't run it, but looks good) but you did something different from what the exercise says. You can notice that by looking at the fact that you create a vector x=[1 2 3 4 5] but you don't use it any more, so why do you need to create it? I...

Hi, What is the value of $t$ for parametrizing the point $(-1,1)$ that is in the parabola?It seems that you are thinking about parametrization just in one direction, you need any point given by the parametrization map being in the object you want to parametrize, but you also need that for any...

Well, That's a valid option, but there is a simpler way to do this with just one instruction. If I give you a vector, say $v=ones(10,1)$, then you can select, for example the first five components with the command $v(1:5)$, or the 2-7 components by writing $v(2:7)$, and so on. So you can do...

So you have created two matrices and have two original vectors. Have you tried to do what the exercise told you to use? Make a couple of combinations and see how .^ work and you will soon see the answer, that is, do what your teacher want you to do :)

Hi, A hint: A matrix in MATLAB it's just a sequence of coordinates paired with the object in that coordinate. So you can manipule this pairings in order to get whatever you want. In this case, change just a part of the matrix. So you want to change the elements $y(i,j)$ for $1 \leq i \leq 2$...

Hi, There is nothing wrong in your code. The results are different because they are different in general, the scalar product of two vectors is the sum of the product of its components.