Question

1. Write the first four terms of the sequence whose general term is given.

an = 7n – 4


2. Write a formula for the general term (the nth term) of each geometric sequence. Then use the formula for an to find the eighth term of the sequence.
1, 2, 4, 8, …

Answer 1

a₁ = 7(1) - 4
a₂ = 7(2) -4
a₃ = 7(3) - 4
a₄ = 7(4) - 4

Thus the four first term of the sequence are 3, 10, 17, 24


`X_(n) = a r ^((n-1))` where a is the first term 1, r is the common ratio 2, and n is the nth term of the sequence.



`X_(8) = (1) 2 ^((8-1))`
= 2⁷
= 128
Thus the eighth term of the sequence is 128