Solution for Problem 8.2.1

Write the first five terms of the sequence.   an = n2 + 3n

Solve

            Step

a1 = 12 + 3(1) = 1 + 3 = 4

Start with n = 1
a2 = 22 + 3(2) = 4 + 6 = 10  n = 2
a3 = 32 + 3(3) = 9 + 9 = 18 n = 3
a4 = 42 + 3(4) = 16 + 12 = 28 n = 4
a5 = 52 + 3(5) = 25 + 15 = 40 n = 5

The first five terms are 4, 10, 18, 28, 40