Question

Fiona has proved that a function, f(x), is an arithmetic sequence. How did she prove that?

She showed that an explicit formula could be created.
She showed that a recursive formula could be created.
She showed that f(n) ÷ f(n − 1) was a constant ratio.
She showed that f(n) − f(n − 1) was a constant difference.

Answer 1

The defining characteristic of any arithmetic sequence is called the common difference.  It is a constant difference found between any term and the term preceding it.

"She showed that f(n)-f(n-1) was a constant difference."