I am looking for a software to sketch moving figures as this one. Thanks. See also:

This seems really simple but I can't get it $$\int_0^{ \pi/2} \cos^2 x \,dx$$ $u = \cos^ 2 x$, $du = -2 \cos x \sin x$ $dv = dx$, $v = x$ $$x \cos x ...

I'm solving the differential equation $y'' + y = 8\cos(x) \cos(2x)$ I started to find the homogeneous solution: We search the zeros of the ...

A Laplace transform property: $f(at)\leftrightarrow \frac{1}{a}F(\frac{s}{a})$ where $f\leftrightarrow F$. Question: Is $a>0$ necessary for this property?

I have two questions. Suppose I have an arithmetic sequence $11,20,29,38,...$ and $11+20+29+38+... = 8998$. How can I find the first $n$ terms that would ...

I found the following problem: Is it possible to partition every convex polygon into a finite number concave quadrilaterals? The answer seems negative, be...

On this free body diagram, how am I able to see that the two angles $\alpha$ are equivalent? I have read about transversals, but I still can't see on...

In reading Hartshorne,a topological space is quasi-compact if each open cover has a finite subcover(P80).Isn't it the definition for compactness of t...

A function $f(x)$ is defined so that $$ f(x) = f(x - 2) - x(x + 2) $$ for all the integer values of $x$ and $f(1) + f(4) = 0$. What is the value of $$f(1)...

How can I find the steady states? I am aware that the condition is to equal 0 but I am not able to say how many steady states there are... $$\begin{cases}...