Math Problem Statement

  1. find the 8th term of the series 1/8, 1/4, 1/2 ..

Solution

The given series is:

18,14,12,\frac{1}{8}, \frac{1}{4}, \frac{1}{2}, \dots

This is a geometric sequence where the first term a1=18a_1 = \frac{1}{8}, and the common ratio rr can be found by dividing the second term by the first:

r=1418=2r = \frac{\frac{1}{4}}{\frac{1}{8}} = 2

The formula for the nn-th term of a geometric sequence is:

an=a1rn1a_n = a_1 \cdot r^{n-1}

To find the 8th term (a8a_8):

a8=18281=1827=18128=16a_8 = \frac{1}{8} \cdot 2^{8-1} = \frac{1}{8} \cdot 2^7 = \frac{1}{8} \cdot 128 = 16

So, the 8th term of the series is:

16\boxed{16}

Would you like further details on geometric sequences or have any questions?

Here are 5 related questions for practice:

  1. What is the 10th term of the series 2,4,8,2, 4, 8, \dots?
  2. How do you find the sum of the first nn terms in a geometric series?
  3. What is the common ratio in the sequence 3,6,12,3, 6, 12, \dots?
  4. How do you determine if a sequence is geometric?
  5. What is the 6th term of the sequence 5,15,45,5, 15, 45, \dots?

Tip: When working with geometric sequences, always double-check the common ratio before applying formulas.

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Math Problem Analysis

Mathematical Concepts

Geometric Sequences
Common Ratio
Exponents

Formulas

nth term of geometric sequence: a_n = a_1 * r^(n-1)

Theorems

Geometric Sequence Theorem

Suitable Grade Level

Grades 8-10