Real numbers x and y, f(x+y)=f(x)+f(y)+1. If f(1)=2, what is f(3)?

[Xasuke]

Ok, I'm sure this is an easy problem and all, but it's pissing me off. I'm probably just not understanding it.

The function f has the property that for any real numbers x and y, f(x+y)=f(x)+f(y)+1. If f(1)=2, what is f(3)?

help.

 

[Tide]

Just use the information provided to find f(2) from which f(3) = 8 follows.

 

[Xasuke]

wow... I feel completely lost.
How do I find f(2)?

 

[dav2008]

f(2)=f(1+1)

If you are given that f(x+y)=f(x)+f(y)+1

then it would be logical to conclude that

f(1+1)=f(1)+f(1)+1 and I think you can take it from there

 

[Xasuke]

Oh my.. Thanks. I'm such an idiot =)