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Jul
20
comment Rewriting Triple Integral in different order
think about the region this represents and represent it using the different variable order; the integrand does not change
Jul
17
comment Find a non injective function between a set of integers and itself
pigeonhole principle implies this is impossible
Jul
17
comment Prove/disprove: if $X$ is an eigenvector of $T$ then X is a singular matrix
@Mnifldz i don't think so, $T$ maps matrix to matrix
Jul
16
comment Question on how to manipulate terms in this expression
Well, doesn't each of those sums depend on $x$? So the only constant seems to be $1/2^n$
Jul
16
comment Question on how to manipulate terms in this expression
i don't understand the question. constants wrt what quantity? $x$?
Jul
16
comment Upper bounding a definite integral
@IvoTerek it does, it's zero over $[0,1]$
Jul
16
comment Upper bounding a definite integral
if you just bound $f \leq 2$ then you get $$\int_0^5 2x = 25$$ which is better than your bound slightly, but still not good enough for $24$
Jul
16
comment Upper bounding a definite integral
@angryavian you're right
Jul
16
comment Upper bounding a definite integral
Must be, you didn't use the bound on $f$ at all
Jul
16
comment Upper bounding a definite integral
@angryavian it is actually $20\sqrt{5}/3 \approx 14.9 < 24$, so must have a bug
Jul
14
comment Conditional probability density function of X given Y = y
Please use LaTeX to typeset :)
Jul
14
comment Maximum/Minimum on a Unit Disk
@Shrey very late tonight, if I have time
Jul
14
comment Maximum/Minimum on a Unit Disk
@Shrey yes. But notice how this answer creatively transformed your circular boundary (which was hard to work with) into a box (which should be much easier).
Jul
14
comment Maximum/Minimum on a Unit Disk
@Shrey here is one half of an example for your case.
Jul
13
comment Variance and Covariance of Linear Transformations
@AlyssaWallace don't calculate it, factor $k^2$ out of both terms and see what remains.
Jul
13
comment Find eigenvalues and eigenvectors of this matrix
@StevenGubkin of course, once you are in a span, any 3 lin.indep. members will form a basis, but I wanted to show an easy way to construct one, which is untuitive and direct...
Jul
13
comment Find eigenvalues and eigenvectors of this matrix
@Kamil exactly :)
Jul
9
comment finding the probability of A happens before B in die rolling
don't they have the same expected waiting times?
Jul
9
comment Existence of Linear Transformation between 3D line and 2D line
@AndyYao yes, you take one of the end points (start there when $t=0$) and when $t=1$ you should end up on the other end point... After you have the parameterization done, your segment become a transformation of $[0,1]$, over which $t$ is defined. Can you then given a point on your segment, produce the corresponding value of $t$, which you can map to the second segment.
Jul
8
comment Representing any number in $R_+$ by means of two numbers
Looks like fixing $a,b$ and letting $n,m$ vary