#### iceman

Hello everyone, this one might seem easy to you but it's driving me insane.

Q) Suppose f(x)=int(1/t.dt)

where the upper limit=x, lower limit=1 ; for x>0.

Without evaluating the integral show that

for any x,y>0, f(x)+f(y)=f(xy).

where you may consider a substitution s=xt in the left-hand side.

Thanks for your help in advance.

Q) Suppose f(x)=int(1/t.dt)

where the upper limit=x, lower limit=1 ; for x>0.

Without evaluating the integral show that

for any x,y>0, f(x)+f(y)=f(xy).

where you may consider a substitution s=xt in the left-hand side.

Thanks for your help in advance.

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