Homework Statement
If all vertices of planar graph have degrees greater than 4, prove if
that graph has at least 12 vertices with degree of 5.
Homework Equations
d1+d2+...+dn= 2*m (m - number of edges, di-degree of i-vertex)
f=2-n+m, f - number of faces, n-number of vertices
The...
Homework Statement
Prove if there exists an integer whose decimal notation contains only 0s and 1s, and which is divisible by 2009.
Homework Equations
Dirichlet's box principle :confused:
The Attempt at a Solution
I'm new to number theory, and I'm aware that I do not have the...
Well, thanks a lot, it seems correct!
Meanwhile, I did it too...
According to Euler's Theorem:
5^{p^{2}-p}\equiv 1(mod\ p^{2})
5^{p^{2}}\equiv 5^{p}(mod\ p^{2})
5^{p^{2}}-5^{p}\equiv 0(mod\ p^{2})
5^{p^{2}}+1-(5^{p}+1)\equiv 0(mod\ p^{2})
So, if 5^{p^{2}}+1 is divisible by p2, then...
Homework Statement
First of all, hi everyone!
I'm quite new in number theory, and need help on this one badly...
Determine all prime numbers p so p2 divides 5p2+1.
Homework Equations
Euler's theorem: If a and m are coprimes then...
Thanks, and that's what I did... now I got...
u=e^{-{\frac{y^2}{2}}}cos(xy)C_1
solving by u_y^'
u=e^{\frac{x^2}{2}}cos(xy)C_2
solving by u_x^'
C_1,C_2 constants
C_1=e^{D_1},C_2=e^{D_2}
so I have functions...
f(z)=e^{D_1-\frac{y^2}{2}+ixy}
f(z)=e^{D_2+\frac{x^2}{2}+ixy}
How two...
1. This is something from complex analysis: Find the analytic function f(z)= f(x+iy) such that arg f(z)= xy.
2. w=f(z)=f(x+iy)=u(x,y)+iv(x,y) (*), w=\rho e^{i\theta} (**)
Here are the Cauchy-Riemann conditions...
\frac{\partial u}{\partial x}=\frac{\partial v}{\partial...
Volume Integral! Help!
I need help with this:
Find volume of figure bounded with surface (x^2+y^2+z^2+1)^2=8*(x^2+y^2)
I tried Ostrogradsky, and spherical coordinate system with it, but I can't find boundaries...
PLEASE! HELP ME!