3, 6, 11, 18,... The first four terms of a sequence are shown above. Which of the following could be the ?

Question

3, 6, 11, 18,... The first four terms of a sequence are shown above. Which of the following could be the formula that gives n th term of this sequence for all the positive integers n? 
A) 2n 
B) 2n + 1
C) 3n
D) n2 ( n to the 2nd power) + 1
E) n2 (2nd power) + 2
this is too much for me and I need help does anyone know this?? And how they got the answer??

MICHAEL R · Accepted Answer

The choice is E

1^2 + 2 = 1 + 2 = 3
2^2 + 2 = 4 + 2 = 6
3^2 + 2 = 9 + 2 = 11
4^2 + 2 = 16 + 2 = 18

Anonymous · Answer

It would be 'B' 
-from 3 to 6 the difference is 3. if 3 is the first term that makes n=1 so 2*1+1=3
-from 6 to 11 the difference is 5. if 6 is the second term that makes n=2 so 2*2+1=5
-from 11 to 18 the difference is 7. if 11 is the third term that makes n=3 so 2*3+1=7
-etc. etc.

Are you taking Calc 2? doing Series and Sequences

lucey · Answer

easyyyy dont hassle the version is +3, +5, + 7 and that all of them have diff of +2 it turns into n squared so n^2 as there are 2 steps to it after which you have +2 as that's the consistent replace so it particularly is n^2 + 2 examine it out to work out if it works

Trending News

3, 6, 11, 18,... The first four terms of a sequence are shown above. Which of the following could be the ?

3 Answers