Problem 5.7

A point source is suspended at a height $h=1.0 \mathrm{~m}$ over the centre of a round table of radius $R=1.0 \mathrm{~m} .$ The luminous intensity $I$ of the source depends on direction so that illuminance at all points of the table is the same. Find the function $I(\theta),$ where $\theta$ is the angle between the radiation direction and the vertical, as well as the luminous flux reaching the table if $I(0)=I_{0}=100 \mathrm{~cd}$.