Question

Tell whether the sequence is arithmetic. If it is, write a function rule to represent it.

0.2, -0.6, -1.4, -2.2

This is an arithmetic sequence, but I do not understand the function rule of A(n) = 0.2 - 0.8(n-1), which is the given answer.

Answer 1

note that each term is 0.8 less than the previous. That means that the formula will look like

A(n) = -0.8n

But, we need A(1) = 0.2
0.2 = -.8 + 1, so
A(n) = 1 - 0.8n

But, most people like n=0 for the first term A(1), so we need to adjust for that, giving the formula above.

Answer 2

what is 996587*968547*6584/85

Answer 3

no idea. get out your calculator, or just type it into google.