# A sequence is defined by the recursive formula f (n + 1) = f(n) – 2. If f(1) = 18, what is f(5)?

Jun 27, 2018

$10$

#### Explanation:

The formula states that the next term in the sequence is generated by subtracting two from the previous one. We know that the first term is $18$, so we have

$f \left(1\right) = 18$

$f \left(2\right) = f \left(1\right) - 2 = 18 - 2 = 16$

$f \left(3\right) = f \left(2\right) - 2 = 16 - 2 = 14$

$f \left(4\right) = f \left(3\right) - 2 = 14 - 2 = 12$

$f \left(5\right) = f \left(4\right) - 2 = 12 - 2 = 10$