Pupil Size When the brightness x of a light source is increased, the eye reacts by decreasing the radius R of the pupil. The dependence of R on x is given by the function
$$
R(x)=\sqrt{\frac{13+7 x^{0.4}}{1+4 x^{0.4}}}
$$
where $R$ is measured in millimeters and $x$ is measured in appropriate units of brightness.
(a) Find $R(1), R(10),$ and $R(100)$
(b) Make a table of values of $R(x)$