The function f(n) = 3f(n-2) - 2f(n-1) , where f(2) = 3 and f(1) = -1 . What is the value of f(5) ?
Plug 5 into the equation:
\(f(5) = 3f(5-2) - 2f(5-1)\)
\(f(5)=3f(3)-2f(4)\)
\(f(3)=3f(1) - 2f(2)\)
\(f(3)=-3 - 6\)
\(f(3)=-9\)
\(f(4)=3f(2) - 2f(3)\)
\(f(4) = 9 +18\)
\(f(4)=27\)
\(f(5)= -27- 54\)
\(\color{brown}\boxed {f(5)=-81}\)