Question

A tree is currently 10 feet tall and grows 2 feet per year. Show your work for full credit.
a. Model this scenario with an arithmetic sequence in explicit form. (2)

b. Rewrite the explicit form of the sequence using function notation. (2)

c. How tall will the tree be in 15 years? (1)

Answer 1

Answer:

(a) An  = 2n +8

(b) F(n) = 10 + (n-1)2

(c) 38ft tall

Step-by-step explanation:

The tree is currently 10 feet long and grown 2 feet per year.

The arithmetic sequence is

10 , 12, 14 , 16 , 18 ..............

a( initial value) = 10 , d (common difference) = 2

Explicit forms

(a) An = a +(n-1)d

     An = 10 + (n-1)2

            = 10 + 2n -2

           An  = 2n +8

(b) F(n) = 10 + (n-1)2

(c) Height of the tree after 15 years

       F(15) = 10 + (15-1)2

                 = 10 + 28

                  = 38ft

So the tree will be 38ft tall after 15 years.