Consider f and g be real – valued functions. Such that f(x + y) +f(x – y) = 2f(x).g(y) ∀x,y∈R .Statement – 1 : If f(x) is not identically zero and |f(x)|≤1 ∀x∈R  then |g(y)|≤1 ∀y∈RStatement – 2 : For any two real numbers x and y |x+y|≤|x|+|y|