Answer:
Step-by-step explanation:
The base case in the recursive function are:
The recursive case is equal to:
So replace 
for 
:
In the new expression 
is a base case so you don't have to worry for that part, but 
is still the recursive case so evaluate again in
and 
are define as base cases so you replace for it's numbers:
Now return to and replace for the new values:
So the final answer is 20
(5x+4y),(5x-4y)
Hope this helps
Answer: 7) 50.27 8) 251.33 9) 235.62 *These answers were calculated using the true value of pi, not 3.14*
