For an 15O PET scan, if an initial dose of 1 mCi is injected, calculate the total number of γ-rays that are produced over a scan time of four minutes, assuming that scanning starts immediately after injection. Hint: Keep in mind that the question is about PET, not SPECT.

Could somebody me with this radical simplification?

Which are the possible side lengths of a triangle?

Question 2 (essay worth 10 points) (03.02 mc) in δabc shown below, point a is at (0, 0), point b is at (x2, 0), point c is at (x1, y1), point d is at x sub 1 over 2, y sub 1 over 2, and point e is at the quantity of x sub 1 plus x sub 2 over 2, y sub 1 over 2: triangle abc is shown. point d lies on segment ac and point e lies on segment bc. a segment is drawn between points d and e. point a is at the origin. prove that segment de is parallel to segment ab.