qeypour 寫到:Anonymous 寫到:qeypour 寫到:f(pq)=f(p)*f(q) require that p,q are primes
Why can you apply this formula to f(p^a*q^b) while p^a,q^b
both are not primes?
It is good question,you can use the same way to extend the formula.
Or, first, you can finish the formula f(p^(a)q)=f(p)Xp^(a-1)Xf(q).
Then, do f(p^(a)q^(b))=f(p^(a))f(q^(b))=f(p)xp^(a-1)Xf(q)q^(-1)
the formula like f(n) defined
f(n)=#{x|1<=x<=n,(x,n)=1}
the function have some theorems.
1. f(p)=p-1;
2. f(pq)=f(p)f(q)
3 if n=p*q*r with p,q,r are different primes
f(n)=n*(1-1/p)*(1-1/q)*(1-1/r)
When you mention out It is good questionas above.
It is clear that you know what I mean.
I am astonished in your answering not understand my question.
no!
Sorry! I really don't know what you mean.
or you can explain what you mean and solve it.
We will appreciate your answer!!