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Feb
5
comment Closed form for $\left(\sum_{k=0}^n\frac{x^k}{k!}\right)^p$
Tried to workout $e^x$ and Newton binomial?
Jan
23
answered Limit of sum of sine terms
Sep
18
comment Prove that $\lim_\limits{x\to 0}{\frac{e^x-1}{x}}=1$ without derivatives
@JackD'Aurizio: If $exp(x) = \sum \frac{x^n}{n!}$ by definition then I agree, but I'm denied un-(-1) the answer.
Sep
16
comment Prove that $\lim_\limits{x\to 0}{\frac{e^x-1}{x}}=1$ without derivatives
-1: op asked not to use derivatives, taylor and related
Sep
7
comment Find a tangent plane
Your function z = f(x,y) plot needs three dimensions. Thus, one contrain become a plane. To say, x=0 is a plane in three dimensions since you can move freely on y and z axis.
Aug
30
comment Solve this integral:$\int_0^\infty\frac{\arctan x}{x(x^2+1)}\mathrm dx$
You are welcome!
Aug
29
comment Solve this integral:$\int_0^\infty\frac{\arctan x}{x(x^2+1)}\mathrm dx$
related: math.stackexchange.com/questions/1403038/…
Aug
29
comment Solve the factorial equation $x! = c$
To prove it's enough observing that $n!$ is strictly increasing for $n \ge 1$, then use @Shailesh 's observation.
Aug
27
answered Solving this Recurrence Relation in terms of previous values.
Aug
25
answered Calculate area of a triangle with just one length and a tangent-relation(?)
Aug
25
comment can a real number be added to a complex number
related for second question
Aug
24
comment Are there reasons not to use product of vectors as dot product?
Thank you, but I should say in my linear algebra course I have never seen the relationship of my question (even if it's quite trivial).
Aug
24
comment Are there reasons not to use product of vectors as dot product?
thank you for proving this example!
Aug
24
answered Why is $1+\cos(\theta)=2\cos^2(\frac{\theta}{2})$
Aug
24
accepted Are there reasons not to use product of vectors as dot product?
Aug
21
comment How to compute the monstrous $ \int_0^{\frac{e-1}{e}}{\frac{x(2-x)}{(1-x)}\frac{\log\left(\log\left(1+\frac{x^2}{2-2x}\right)\right)}{2-2x+x^2}dx} $
Observing $\log\left(\log\left(1+\frac{x^2}{2-2x}\right)\right) = \log(\log(2-2x+x^2) - \log(2-2x))$ could be useful
Aug
20
asked Are there reasons not to use product of vectors as dot product?
Aug
12
answered Can math be learned backwards?
Aug
10
comment Can Lagrange Multiplier method provide a saddle point in two dimensions
take $f(x,y) = x^2 - y^2$, in $(x,y)=(0,0)$. It's a maximum when restricting by imposing $y = 0$, but it's a minimum when restricting by imposing $x = 0$
Aug
8
revised Show $\lim_{m \to \infty ,n \to \infty } f(\frac{{\left\lfloor {mx} \right\rfloor }}{m},\frac{{\left\lfloor {ny} \right\rfloor }}{n}) = f(x,y)$
tag correction