Question

Which function describes the arithmetic sequence shown?

1, −2, −5, −8, −11, ...
A) ƒ(x) = 3x + 4
B) ƒ(x) = 3x − 4
C) ƒ(x) = −3x + 4
D) ƒ(x) = −3x − 4

Answer 1

A

Explanation:

Answer 2

C) ƒ(x) = −3x + 4

Explanation:

The arithmetic sequence has a general form:

f = a + d(x-1)

Where: a is the first term and d is the common difference

For the given arithmetic sequence :

1, −2, −5, −8, −11, ...

a = 1

d = -2 - 1 = -3

So, f(x) = 1 + (-3)(x-1)

∴ f(x) = 1 -3x + 3

∴ f(x) = -3x + 4

The answer is option C) ƒ(x) = −3x + 4