The linear function graphed below represents the value of a comic book since Lucy purchased it. What was the value of the comic book when Lucy bought it? A graph titled Value of Lucy's Comic Book has Years since Lucy bought a comic book on the x-axis, and value (dollars) on the y-axis. Points are at (1, 40), (2, 55), (3, 70), (4, 85).

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)