Identify the 12th term of a geometric sequence where a1 is 8 and a6 is 8192

To find the 12th term of the geometric sequence, we first need to understand the formula for the nth term of a geometric sequence, which is given by:

an = a1 * r(n-1)

Here, a1 is the first term, r is the common ratio, and n is the term number. Given that a1 = 8 and a6 = 8192, we can use this information to find r.

First, let’s use the formula to express a6:

a6 = a1 * r(6-1) = 8 * r5

Setting this equal to 8192 gives:

8 * r5 = 8192

To solve for r5, divide both sides by 8:

r5 = 8192 / 8 = 1024

Next, we need to find r. We can rewrite 1024 as a power of 2:

1024 = 210

Now, since r5 = 210, we can express r as:

r = (210)(1/5) = 22 = 4

Now that we have r = 4, we can find the 12th term:

a12 = a1 * r(12-1) = 8 * 411

Calculating 411:

411 = (22)11 = 222

Now express a12:

a12 = 8 * 222

Since 8 = 23:

a12 = 23 * 222 = 225

Finally, simplifying gives:

a12 = 33554432

Therefore, the 12th term of the geometric sequence is 33,554,432.

More Related Questions