Each section contains pickets.

and .

(a) Find first five terms.

Formula for term of arithmetic sequence . .

.

.

.

.

(b)

Observe the results in part(a),

Recursive formula for term of arithmetic sequence is .

.

(c)

If 448 pickets were used to fence in the customers backyard, then .

There are sections of each feet wide.

feet.

Thus, feet fencing was used.

(a) First five terms of the sequence are .

(b) Recursive formula for term of arithmetic sequence is .

(c) fencing was used.