# How do you find the domain and range for f(x) = 1/(1+x^2)?

Domain: $\mathbb{R}$
Range: 0
The domain of the function is all of $\mathbb{R}$ as no value of $x$ causes the function to be undefined.
The range is 0. For $x = 0$ the function takes the value $1$ and for all x→±∞ the function is decreasing and tends to $0$.