Assignment:
(i) Calculate phi(15) in THREE ways.
(ii) Express in modular arithmetic
[Hint: The number of integers from 1 to m that are relatively prime to m is denoted by phi(m). it is the number of elements in the set a:1=a=m and gcd(a,m)=1 ]
Provide complete and step by step solution for the question and show calculations and use formulas.