April borrows $60 from her grandmother to buy basketball shoes. At the end of the first week, April pays back $5. At the end of each of the following weeks, she pays back $3 more than she did the previous week. The arithmetic sequence 5, 8, 11, 14, . . . can be used to represent this situation. In this sequence n represents what?

Find a parametrization for the curve「and determine the work done on a particle moving along γ in r3 through the force field f: r^3--r^3'where f(x,y,z) = (1,-x,z) and (a) im (γ) is the line segment from (0,0,0) to (1,2,1) (b) im (γ) is the polygonal curve with successive vertices (1,0,0), (0,1,1), and (2,2,2) (c) im (γ) is the unit circle in the plane z = 1 with center (0,0,1) beginning and ending at (1,0,1), and starting towards (0,1,1)