Answer: B. Yes, d = 3
==============================================================
Step-by-step explanation:
d = common difference, which is what we add on each time to get the next term
In this case, d = 3 means we add 3 each time to generate each new term
- -11+3 = -8
- -8+3 = -5
- -5+3 = -2
- -2+3 = 1
This pattern continues on forever.
--------------
Another way to see that d = 3 is to notice this is the difference between any two adjacent terms.
- d = term2 - term1 = -8 - (-11) = -8 + 11 = 3
- d = term3 - term2 = -5 - (-8) = -5 + 8 = 3
- d = term4 - term3 = -2 - (-5) = -2+5 = 3
- d = term5 - term4 = 1 - (-2) = 1 + 2 = 3
Each gap is 3 units wide, which helps us see we have an arithmetic sequence.
A sequence like {-11,-8,-5,-2,2} is not arithmetic because the gap between the terms of -11,-8,-5,-2 is 3, but the gap from -2 to 2 is not 3. So the gap must stay the same the entire time to get an arithmetic sequence.