Answer:
The correct answer with step-by-step explanation:
is in quadrant I, so
.
is in quadrant II, so
.
Recall that for any angle
,

Then with the conditions determined above, we get

and

Now recall the compound angle formulas:




as well as the definition of tangent:

Then
1. 
2. 
3. 
4. 
5. 
6. 
7. A bit more work required here. Recall the half-angle identities:



Because
is in quadrant II, we know that
is in quadrant I. Specifically, we know
, so
. In this quadrant, we have
, so

8. 
2 gallons divided between 9 people would equal 0.222222222 gallons per person
2 more 10s then 11 is 31
1 more 10s then 11 is 21
3 more 10s then 11 is 41.
basic math :)
5 pizzas feeding 20 people means 1 pizza to feed 4 people. 88/4=22 therefore 22 pizzas are needed to feed 88 people.