contestada

A) write an explicit formula for the sequence 12, 16, 20, 24 B) Find the 11th term of the sequence *

Respuesta :

Answer:

[tex]T_n = 8+ 4n[/tex]

[tex]T_{11} = 52[/tex]

Step-by-step explanation:

Given

[tex]Sequence: 12, 16, 20, 24[/tex]

Solving (a): Write a formula

The above sequence shows an arithmetic progression

Hence:

The formula can be calculated using:

[tex]T_n = a + (n - 1) d[/tex]

In this case:

[tex]a = First\ Term = 12[/tex]

Difference (d) is difference of 2 successive terms

So:

[tex]d = 16 - 12 = 20 - 16 = 24 - 20[/tex]

[tex]d = 4[/tex]

Substitute 4 for d and 12 for a in [tex]T_n = a + (n - 1) d[/tex]

[tex]T_n = 12 + (n - 1) * 4[/tex]

Open Bracket

[tex]T_n = 12 + 4n - 4[/tex]

Collect Like Terms

[tex]T_n = 12 - 4+ 4n[/tex]

[tex]T_n = 8+ 4n[/tex]

Hence, the explicit formula is: [tex]T_n = 8+ 4n[/tex]

Solving (b): 11th term

This implies that n = 11

Substitute 11 for n in: [tex]T_n = 8+ 4n[/tex]

[tex]T_{11} = 8+ 4 * 11[/tex]

[tex]T_{11} = 8+ 44[/tex]

[tex]T_{11} = 52[/tex]

Answer:

A) The explicit formula for the sequence is [tex]f(n) = 12+4\cdot n[/tex], [tex]n \in \mathbb{N}_{O}[/tex].

B) The 11th term of the sequence is 62.

Step-by-step explanation:

A) Let [tex]f(0) = 12[/tex], we notice that sequence observes an arithmetic progression, in which there is a difference of 4 between two consecutive elements. The formula for arithmetic progression is:

[tex]f(n) = f(0) +r\cdot n[/tex] (1)

Where:

[tex]f(0)[/tex] - First value of the sequence, dimensionless.

[tex]r[/tex] - Arithmetic increase rate, dimensionless.

[tex]n[/tex] - Term of the value in the sequence, dimensionless.

If we know that [tex]f(0) = 12[/tex] and [tex]r = 4[/tex], then the explicit formula for the sequence is:

[tex]f(n) = 12+4\cdot n[/tex], [tex]n \in \mathbb{N}_{O}[/tex]

B) If we know that [tex]f(n) = 12+4\cdot n[/tex] and [tex]n = 10[/tex], the 11th term of the sequence is:

[tex]f(10) = 12+4\cdot (10)[/tex]

[tex]f(10) = 62[/tex]

The 11th term of the sequence is 62.