[?] Evaluate a function in two variables at a particular point (a,b)?

Questions
1

I need evaluate a a function in two variables in a particular point, I mean, if f(x,y)=x^2+y^2, and p=(1,1), I want to get f(1,1).

2

If you can get your input into this form then

f[x_,y_]:=x^2+y^2;
p={1,2};
f@@p

should give you

5

You can look up @@ or Apply in the help system to find information about how this works

3

Thank you, that works