$$\sum_{n=1}^{\infty}\frac{7}{n(n+3)}$$ I know this is convergent but I do not know how to apply "cover-up method" to solve this can I get some help pls? ...

How can I evaluate the following integral $$ \int_{0}^{\infty} x^{-1/2} \exp({-x/2})\ dx $$ I know the answer is $\sqrt{2\pi}$.

I'm reading a numerical analysis book, which gave me very confusing descriptions about stability and backward stability. It says that an algorithm $f...

The number of triangles whose vertices are the the vertices of the vertices of an octagon but none of whose sides happen to come from the sides of the oct...

Me and a couple of friends have recently started solving Math problems in our breaks at school. We came along the Georg Mohr tournament, which is Denmark&...

How do I find the derivative of the function $f(x)= (2x+1)^2$? I've tried doing this problem and am not fully sure that I am correct. I found the der...

I'm trying to find the parametric equations for a helix around a helix around a circle (helix on helix on circle) That is: I would like to start with...

Possible Duplicate: Division by $0$ I've always been inclined to believe that x/0 = NaN is a placeholder for a character or constant that no one has ...

I'm having trouble converting a vector from the Cartesian coordinate system to the cylindrical coordinate system (second year vector calculus) Repres...

Is there a way of adding two vectors in polar form without first having to convert them to cartesian or complex form?