How to write the sum in sigma notation given a geometric sequence

The video tutorial explains how to write sum notation for a sequence, starting with identifying the first term and the common ratio. It guides through the process of finding the last term and solving for the number of terms (N) using logarithmic properties. The tutorial concludes with a demonstration of solving the sequence using both logarithmic and one-to-one properties.

What is the first term (a1) in the sequence discussed in the video?

• 14

• 2

• 7

• 28

How is the common ratio (r) determined in the sequence?

• By dividing the second term by the first term

• By subtracting the first term from the second term

• By multiplying the first term by the second term

• By adding the first term to the second term

What is the formula used to find the nth term in the sequence?

• a_n = a_1 - r^(n-1)

• a_n = a_1 / r^(n-1)

• a_n = a_1 * r^(n-1)

• a_n = a_1 + r^(n-1)

What is the last term value given in the sequence?

• 128

• 256

• 896

• 512

Which method is used to solve for the unknown term position (N) in the sequence?

• Taking the logarithm of both sides

• Applying the distributive property

• Using the Pythagorean theorem

• Using the quadratic formula