contestada

Consider the recursive formula an = (2 + an-1) / 2
. The first term of the sequence is 10, what is the third term?
A) 1
B) 4
C) 6
D) 8

Respuesta :

Answer: The correct option is B. The third term is 4.

Explanation:

The given recursive formula is,

[tex]a_n=\frac{2+a_{n-1}}{2}[/tex]

It is given that the first term is 10. So,

[tex]a_1=10[/tex]

To find third term, first we have to find the second term.

[tex]a_2=\frac{2+a_{2-1}}{2}[/tex]

[tex]a_2=\frac{2+a_{1}}{2}[/tex]

[tex]a_2=\frac{2+10}{2}[/tex]

[tex]a_2=\frac{12}{2}[/tex]

[tex]a_2=6[/tex]

Therefore the second term is 6.

[tex]a_3=\frac{2+a_{3-1}}{2}[/tex]

[tex]a_3=\frac{2+a_{2}}{2}[/tex]

[tex]a_3=\frac{2+6}{2}[/tex]

[tex]a_3=\frac{8}{2}[/tex]

[tex]a_3=4[/tex]

Therefore, the correct option is B. The third term is 4.