The number of real linear functions f(x) satisfying `f(f(x)) = x + f(x)` is

The number of linear functions f satisfying f(x+f(x))= x + f (x) AA x in R is a)0 b)1 c)2 d)3

The number or linear functions f satisfying f(x+f(x))=x+f(x) AA x in RR is

The number or linear functions f satisfying f(x+f(x))=x+f(x) AA x in RR is

The number or linear functions f satisfying f(x+f(x))=x+f(x) AA x in RR is

The number or linear functions f satisfying f(x+f(x))=x+f(x) AA x in RR is

The number of linear functions of f satisfying f(x+f(x))=x+f(x) for all x in R is

The number of functions f:R rarr R satisfying f(x+y)=f(x)f(y)f(xy) where x,y in R and R is the set of real numbers is

Find the period of the real valued function satisfying f(x)+f(x+4)=f(x+2)+f(x+6)