Given the function `f(x)=(a^x+a^-x)/2 (a> 0)`. If `f(x + y) + f(x-y) = k f(x). f(y)` then k has the value equal to

If f(x + y) = f(x) +f(y), then the value of f(0)

Given the function f (x) =(a ^(x) + a ^(-x))/(2), a gt 2, then f (x+y) + f(x -y) =

Given the function f (x) =(a ^(x) + a ^(-x))/(2), a gt 2, then f (x+y) + f(x -y) =

Given the function f(x)=(a^(x)+a^(-x))/(2) ( where a gt 2 ). Then f(x+y)+f(x-y)=

If f(x)=(a^(x))+a^(-x)/(2) and f(x+y) +f(x-y)=Kf(x) f(y) , then the value of K.

If f(x)=(a^(x)+a^(-x))/(2) and f(x+y)+f(x-y)=kf(x)f(y) then k=

Given the function f(x)=(a^(x)+a^(-x))/(2)(wherea>2)dot Then f(x+y)+f(x-y)= (A) 2f(x).f(y) (B) f(x).f(y) (C) (f(x))/(f(y)) (D) none of these