Answer: 15625
Work Shown:
Plug in n = 2 and compute
f(n)=5f(n-1)
f(2)=5*f(2-1)
f(2)=5*f(1)
f(2)=5*5
f(2)=25
Repeat for n = 3
f(n)=5f(n-1)
f(3)=5*f(3-1)
f(3)=5*f(2)
f(3)=5*25
f(3)=125
Do the same for n = 4
f(n)=5f(n-1)
f(4)=5*f(4-1)
f(4)=5*f(3)
f(4)=5*125
f(4)=625
And also n = 5
f(n)=5f(n-1)
f(5)=5*f(5-1)
f(5)=5*f(4)
f(5)=5*625
f(5)=3125
Then finally n = 6
f(n)=5f(n-1)
f(6)=5*f(6-1)
f(6)=5*f(5)
f(6)=5*3125
f(6)=15625
This is the final answer.
Side note: The closed-form shortcut formula is
f(n) = 5^n
Note how
f(n) = 5^n
f(6) = 5^6
f(6) = 15625