Functions

Please prove property (ii)


@ashishdeosingh
I can't understand the 2nd last line
How df/dx=f(x)×k/x
From where k came

@nishantthakre
left side it is f’(x) which is nothing but df/dx

@ashishdeosingh
From where k came

f’(1)=k which is some constant

Can you tell me which book is that?

@miltonsermoud
Arihant skill in mathematics by Amit M Agrawal