The expression cos(a-b) - cos(a+b) is equal to

1) -2sinasinb
2) -2cosb
3) 2cosacosb
4) 2sinasinb

so far, all i've gotten is

cosxcosy + sinxsiny - cosxcosy - sinxsiny

i don't know where to go from there. i'm assuming that's zero, and i don't know which of the others equal they all look the same.

we'll this would mean that the dunk tank and the bounce house are the same for 20 hours because the 2 represents that the two activities, and the 20 represents the amount of hours they both are. so with this said, it means that the answer is c. the costs for a dunk tank and bounce house are the same for 20 hours.

c.the costs for a dunk tank and bounce house are the same for 20 hours.

hope this .

i think it might be a but you might want a second opinion