Question

Are my answers correct if not which are right?

Find the second difference for the sequence.

7, 6, 7, 10, 15, 22, ….


1

2

3

5
answer:a


Find first differences for the sequence in order from a1 to a5. Determine whether or not the series is quadratic or not.

-1, -3, -1, 5, 15


2, 2, 6, 10; not quadratic

2, 2, 6, 10; quadratic

-2, 2, 6, 10; not quadratic

-2, 2, 6, 10; quadratic

answer: d


Find a quadratic model for the sequence.

-4, -4, -3, -1, 2
________________________________________

y = 0.5x2 - 0.5x - 4

y = 0.5x2 - 1.5x - 3

y = 4.5x2 - 21.5x+21

y = -4.5x2 + 21.4x - 21

answer: b

Answer 1

see your previous post under anonymous