# How do you find the domain and range of f(x)=sqrt(8-x)?

The domain is $8 - x \ge 0$ or $8 \ge x$ hence ${D}_{f} = \left(- \infty , 8\right]$
and the range is $f \left(x\right) = \sqrt{8 - x} \ge 0$ or ${R}_{f} = \left[0 , + \infty\right)$