Is there any function (if any) f: Z -> Z such that
f(f(n))=-n , for every n belongs to Z(integers) ??
I think that there is not any function like the one described above but how can we prove it. Any ideas??
Thanks in Advance
Homework Statement
How can we found the length of the curve:
f(x) = \frac {1}{12}(x - 48)\sqrt x
where x\ge0 and the vertical line x=48.
Homework Equations
The Attempt at a Solution
I tried to use the formula L=\int^{48}_{0}\sqrt {1 + \ [f'(x)]^2} dx
But I think that...
Homework Statement
I'm a little a bit confused about the following exercise because of the two segments of the function. How can we find the Laplace transform of this function
f(t) = \begin {cases} t , 0\le t < 4 \\
5 , t\ge 4\end {cases}
Homework Equations
The Attempt at a...
Ptolemy metric space. Help!
The problem is :
"Let x,y,z,t belongs to R^n where d(x,y)=||x-y||.
Show that(Ptolemy's inequality):
d(x,y)d(z,t)<=d(x,z)d(y,t)+d(x,t)d(y,z)"
I have found this related to the topic paper but I cannot show that the Euclidean space R^n is Ptolemy.
The paper...