If #f(1) = 3# and #f(n) = -2f(n-1) + 1#, what is #f(5)#?

1 Answer
Aug 6, 2016

#f(5)=43#

Explanation:

#f(1)=3#

#f(n)=-2f(n-1)+1#

#f(2)=-2f(1)+1#

#f(2)=-2(3)+1=-6+2=-5#

#f(3)=-2f(2)+1#

#f(3)=-2(-5)+1#

#f(3)=11#

#f(4)=-2(f(3))+1#

#f(4)=-2(11)+1#

#f(4)=-22+1=-21#

#f(5)=-2(f(4))+1#

#f(5)=-2(-21)+1#

#f(5)=42+1#

#f(5)=43#