6. If A + B + C = 180°, show that
a)
cos A sin B sin C + cos B sin C sin A + cos C sin A sin B = 1 + cos A cos B cos C

Tom is the deli manager at a grocery store. he needs to schedule employee to staff the deli department for no more that 260 person-hours per week. tom has one part-time employee who works 20 person-hours per week. each full-time employee works 40 person-hours per week. write and inequality to determine n, the number of full-time employees tom may schedule, so that his employees work on more than 260 person-hours per week. graph the solution set to this inequality.