Question

The nth term of a sequence is 2n2 − 1 The nth term of a different sequence is 40 − n2 Show that there is only one number that is in both of these sequences.

Answer 1

Answer:

Step-by-step explanation:

nth term of a sequence = 2n² - 1

Therefore, terms of the sequence will be,

1, 7, 17, 31, 49, ........... n terms

nth term of a different sequence = 40 - n²

Therefore, terms of the sequence will be,

39, 36, 31, 24, 15, 4, -9, -24 .......... n terms  

Since, there is no negative number in the first sequence,

Therefore, out of 6 positive terms of second sequence only one number (31) is common in both the sequences.