# What is the domain and range of f(x) = 1 + tan^2 x?

The domain of the tangnet is: $x \ne \frac{\pi}{2} + k \pi$.
The range of this function is $\left[1 , + \infty\right)$, and this is because the function ${\tan}^{2} x$ has range $\left[0 , + \infty\right)$ because it is a square, and there is the $1$...