Question

Write the first five terms of each of the sequences in Exercises 1 to 6 whose nth terms are: an = (-1)n - 1 5n + 1.

Answer 1

Substituting n = 1, 2, 3, 4, 5, we obtain

a1 = (-1)1-1 51+1 = 52 = 25

a2 = (-1)2-1 52+1 = -53 = -125

a3 = (-1)3-1 53+1 = -54 = 625

a4 = (-1)4-1 54+1 = -55 = -3125

a5 = (-1)5-1 55+1 = 56 = 15625

Therefore, the required terms are 25, –125, 625, –3125, and 15625.