Critical Thinking

A spherical target in a body is being targeted with $\beta^{+}$ radiation. The target is centered at $(\text{0} .\text{00},\textrm{ }\text{2} .\text{00},\textrm{ }\text{3} .\text{00})$ on a grid that is in centimeters. The target has a radius of 0.500 centimeters. (a) What two points on the x-axis are at the extremes of where the positrons annihilate the electrons? (b) What two points on the y-axis are at the extremes of where the positrons annihilate the electrons? (c) What can be said about the directions of the pair of gamma rays that result from the annihilations? (d) Can the use of $\beta^{+}$ give information in three dimensions?