As far as I understand, the following is my personal definition for limits/limiting-values: If the value of a function cannot be determined for any value ...

Definition: The closure of a set $A$ is $\bar A=A\cup A'$, where $A'$ is the set of all limit points of $A$. Claim: $\bar A$ is a closed set. Pr...

Suppose that $s$ is a step function, and $f(x)=mx+k$. How to prove that $s(f(x))$ is step function also? Edit: Definition of step function: Function $s$ d...

Use algebra to calculate the perimeter of a right angle triangle where the hypotenuse is $(x+4)$, the base is $(x+3)$ and the remaining side is $(x-4)$. T...

By definition, the double factorial $(-1)!! = 1$. How can this be rationalized?

How can I calculate the derivatives $$\frac{\partial \mbox{erf}\left(\frac{\ln(t)-\mu}{\sqrt{2}\sigma}\right)}{\partial \mu}$$ and $$\frac{\partial \mbox{...

I have a problem on reading a contour plot. I have tried to learn about it on some sites but i still can't understand it. Please any help to fill in ...

I have this question that says $f(x,y,z)$ such that $\nabla f(x,y,z) = <2xy,2yz+x^2,y^2>$ The way I see this is that they are asking for what can yo...

Can someone, please, explain in simple words what spectral leakage is? I am interested in the case where a window is used to reduce the truncation error o...

I have been looking for a concrete answer on this matter since leaving secondary school and thought now to ask online since YouTube and Wikipedia seem too...