To simplify the description of the domain, we may note that
is the equation of a circle of radius in the -plane centered at the origin.
Find the domain of the function f(x,y) = square root(y) + square root(25-x^2 - y^2)
square root(y) is defined only when y equal or > then 0.
square root(25-x^2 - y^2) is defined only when 25> or equal to x^2+y^2
so the domain of f is {(x,y) | y>,eqaul to 0, x^2+y^2<,equal to 25}
Did I make a mistake here?