Do we always have to use "LIATE" to do integration by parts?
Do we always have to use "LIATE" to do integration by parts? L = logarithms I = inverse trigonometric functions A = algebraic functions T = trig...
Category: News
General form for $\sin(kx)$ in terms of $\sin(x)$ and $\cos(x)$
Identities for $\sin(2x)$ and $\sin(3x)$, as well as their cosine counterparts are very common, and can be used to synthesize identities for $\sin(4x)$ an...
Probability of picking rooms
Suppose there are 15 rooms among which a person in present in one room. If i pick 5 rooms out of them, what is the probability that the person is present ...
"Doubling" a graph into a bipartite graph - is there a name for it?
Given a directed graph $\mathcal{G}=(N,A)$ with $N=\{v_1,\dots,v_n\}$, is there a standard name for the bipartite graph $\mathcal{B}=(N,N',A')$ ...
Why does a tangent intersect a circle only at one point?
This might seem like an inappropriate question and even though its easy to retort using analytic geometry, I don't feel convinced that a tangent real...
Conformal mapping onto lower half plane
How to conformaly mapping region $$D = \{|z|>1,\Im z > 0\}$$ on lower half plane? Any suggestions? Thanks in advance.
Is the matrix $A$ positive (negative) (semi-) definite?
Given, $$A = \begin{bmatrix} 2 &-1 & -1\\ -1&2 & -1\\ -1& -1& 2 \end{bmatrix}.$$ I want to see if the matrix $A$ positive (negativ...
Conversion from 2-dimensional parabolic coordinates to cartesian and cylindrical
I have been looking at the Wolfram Mathworld page on parabolic coordinates here: http://mathworld.wolfram.com/ParabolicCoordinates.html and I'm havin...
Math definition for "positive or negative"
If you define a direction on a plane as either positive or negative, what would you call its positive/negativeness? Its orientation? I feel like there is ...
Correlation matrix from Covariance matrix
This is for a project which I've been trying to find some information for Covariance matrix and correlation matrix. I understand that for a $n \times...
