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1d
answered adding a “negative area” and a positive area when the two are infinite
1d
comment Problem on Time and Work
@Iaamuseruser What is wrong with that? It won't be that lengthy. OK, the (slightly) shorter version: You know that after two days, one day with help from $B$ and one day with help from $C$, $\frac{17}{60}$ work has been done. After two more days (identical to the first two days), $\frac{34}{60}$ work has been done. Two more days, and $\frac{51}{60}$ has been done, and you know that you're close.
1d
comment Problem on Time and Work
@Iaamuseruser How much work is done the third day? The fourth day? Carry on until you reach a total of $\frac{60}{60}$ work done.
1d
answered Problem on Time and Work
1d
comment what is a complex number in layman terms?
@Crostul That would, in Daniel's interpretation, mean that you owe someone almost $3\frac17$ apples.
1d
comment what is a complex number in layman terms?
@Daniel In that case, $i$ is the number of apples of each side in an apple square that has total area "one apple in debt"?
1d
comment what is a complex number in layman terms?
Before you even start with complex numbers, can you understand negative numbers? What would $-3$ apples mean? At some point you just have to accept an abstraction, and stop thinking about numbers as "how many of something there are".
1d
comment Prove $\lim_{n \to \infty} \frac{4n^3}{2n^2+1} \sin(\frac{\pi}{n}) = 2\pi$
@copper.hat How so? $\frac{\sin x}{x}$ is the classical example of a limit where Taylor / l'Hopital doesn't really help (unless your $\sin x$ is defined from the Taylor series), so you need something else to calculate it.
2d
revised How do I show that if $f$ is bounded and integrable on $\mathbb{R}$, then $g(t) = \int_t^{t+1} f(x) dx$ is continuous?
rolled back to a previous revision
Feb
11
comment Which of the following can NOT be the possible value of $P(A \cup B)$?
If $A$ is a special case of $B$, then $P(A\cup B) = P(B)$.
Feb
10
comment Example of submodule which has higher “rank” than the module
@user26857 I missed that $M_0$ didn't have to be free. As you said, that cannot be done, and I didn't realise that there is more than one way to decompose $0$ in my examples of $M_0$. So David Hill's example works just fine.
Feb
10
comment why are the Bisection and Newton Method for finding roots complementary to each other?
What would "complementary" mean? That when one works well, the other one doesn't?
Feb
10
revised Explain “homotopy” to me
Dollar signs are not meant for italics.
Feb
10
comment Proof using the laws of set algebra.
By "set laws", what exactly do you mean? There are many different sets of set laws.
Feb
10
comment How can I find the maximum/minimum and maximal/minimal elements of a poset?
As for the funny $\leq$, do you mean $\preceq$ (\preceq)? Googling "detexify" brings you to this site which is a wonderful tool for that one symbol you don't remember or know how to do.
Feb
10
comment A is a square matrix and given that $A^3 = 2\mathbb{I}$, then show $A-\mathbb{I}$ is invertible and find its inverse
We are told that $A^3 = 2I$. See if you can wrestle out $(A-I)\cdot B = I$ from that somehow, for some $B$.
Feb
10
revised Prove that $\lim_{x\rightarrow \infty} \frac{x^2 - 1}{x^2 + 1} = 1$ using definition of limit.
added 120 characters in body
Feb
10
answered Prove that $\lim_{x\rightarrow \infty} \frac{x^2 - 1}{x^2 + 1} = 1$ using definition of limit.
Feb
10
revised Prove that $\lim_{x\rightarrow \infty} \frac{x^2 - 1}{x^2 + 1} = 1$ using definition of limit.
edited title
Feb
10
revised If $1,-1,0$ are eigen values of $A$ then $\det(I+A^{100})=$?
added 4 characters in body