Write the first five terms in each of the following sequence: a1 = a2 =2, an = an–1 – 1, n > 2
Write the first five terms in each of the following sequence: a1 = a2 =2, an = an–1 – 1, n > 2

Answer:

Using n = 1, 2, 3, 4, 5, the first five terms can be calculated.

If n = 1,

a1 = 2

 

If n = 2,

a2 = 2

If n = 3,

a3 = a3–1 – 1

= a2 – 1

= 2 – 1

= 1

If n = 4,

a4 = a4–1 – 1

= a3 – 1

= 1 – 1

= 0

If n = 5,

a5 = a5–1 – 1

= a4 – 1

= 0 – 1

= -1

∴ First five terms of the sequence are 2, 2, 1, 0, -1.