A 13-foot ladder extends from the ground to the top of an 8-foot wall. Which expression could be used to determine the angle, in degrees, between the top of the ladder and the top of the wall?

a. sin(8/13
b. cos(8/13)
c. arccos(8/13)
d. arcsin(8/13)

Asmall business produces and sells balls. the fixed costs are $20 and each ball costs $4.32 to produce. each ball sells for $8.32. write the equations for the total cost, c, and the revenue, r, then use the graphing method to determine how many balls must be sold to break even.