Question

What are the first four terms of the sequence shown below?

an = n^3 + ^2
A.
1, 2, 3, 4
B.
1, 12, 15, 20
C.
2, 12, 36, 80
D.
5, 10, 15, 18

Answer 1

`a_(n) = n^(3) + n^(2)`

`a_(1) = 1^(3) + 1^(2)`

= 1 + 1

= 2

`a_(2) = 2^(3) + 2^(2)`

= 8 + 4

= 12

`a_(3) = 3^(3) + 3^(2)`

= 27 + 9

= 36

`a_(4) = 4^(3) + 4^(2)`

= 64 + 16

= 80

Answer: C