Product of divisors number theory problem

lei123
Messages
11
Reaction score
0

Homework Statement


prove using induction:
for any n =1,2,3...
the product of the divisors of n = n^(number of divisors of n (counting 1 and n)/2)


Homework Equations





The Attempt at a Solution


I understand why this is the case, but I'm having trouble with the induction step.
if the product of the divisors of k = k^(number of divisors of k/2), the the product of the divisors of k+1 = k^(number of divisors of k+1/2). I know that k and k+1 are relatively prime, so all their divisors are different. But I can't seem to make that final connection
 
Physics news on Phys.org
hi lei123! :smile:

i've no idea why anyone would want to prove it by induction :confused:

but if you do, then as you say, using induction on the number n itself won't work, so how about doing it on the number of divisors, or on the number of prime factors?
 
Prove $$\int\limits_0^{\sqrt2/4}\frac{1}{\sqrt{x-x^2}}\arcsin\sqrt{\frac{(x-1)\left(x-1+x\sqrt{9-16x}\right)}{1-2x}} \, \mathrm dx = \frac{\pi^2}{8}.$$ Let $$I = \int\limits_0^{\sqrt 2 / 4}\frac{1}{\sqrt{x-x^2}}\arcsin\sqrt{\frac{(x-1)\left(x-1+x\sqrt{9-16x}\right)}{1-2x}} \, \mathrm dx. \tag{1}$$ The representation integral of ##\arcsin## is $$\arcsin u = \int\limits_{0}^{1} \frac{\mathrm dt}{\sqrt{1-t^2}}, \qquad 0 \leqslant u \leqslant 1.$$ Plugging identity above into ##(1)## with ##u...
Back
Top