Question

f(y+x)+f(y-x)=2f(x)f(y)

what's f(x)?

Answer 1

Represents a function in respect to a variable, in that case x

Answer 2

To make my question more clear, what is the function that satisfies this functional equation...

Answer 3

I think he's trying to be funny?

Answer 4

lol beats me.

Answer 5

Obviously distribute the f first...noobs.

Answer 6

f(y+x)+f(y-x)=2f(x)f(y)

fy+fx+fy-fx=2f^2xy

2fy=2f^2xy

1=fx

f=1/x

solved! ty @iambatman

Answer 7

loooool, np :)