Find the domain of the function. Write your answer in interval notation. (If you need to enter ∞ or -∞, type INFINITY or -INFINITY.)

Question

Find the domain of the function. Write your answer in interval notation. (If you need to enter ∞ or -∞, type INFINITY or -INFINITY.) 
f(s,t)= sqrt(s^2+t^2) 
s = ? 
t = ?

Steve · Answer

you need s^2+t^2 >= 0 can you think of any real values for s or t where that would not hold?