Question

A sequence is defined recursively by the formula f(n+1)=-2f(n). The first term of the sequence is -1.5. What is the next term in the sequence?

Answer 1

just use the definition.
f(1) = -1.5
f(2) = -2f(1) = -2(-1.5) = 3
f(3) = -2f(2) = -6
and so on