Question

@hartnn
Find an explicit rule for the nth term of the sequence.

7, 21, 63, 189, ...

Answer 1

can u see any pattern ?

Answer 2

multiplying by 3

Answer 3

Yep^^^^^^^^

Answer 4

so, the common ratio =r =3

(you know whats common ratio?)

first term = a1 = 7

Answer 5

use this formula
\(\Large a_n = a_1 r^{n-1}\)
General n'th term formula for geometric sequence.

Answer 6

so, \(\sf 7*3^{n-1}\)

Answer 7

yep :)