Equations for Geometric Sequences

Write the explicit formula for the geometric sequence.

• a_n = 10(2)^n-1

• a_n = 2(10)^n-1

• a_n = 10(2)ⁿ

• a_n = 2(10)ⁿ

Write the explicit formula for the geometric sequence.

• a_n = 4(3)^n-1

• a_n = 3(4)^n-1

• a_n = -4(3)^n-1

• a_n = 3(-4)^n-1

Given the sequence: 125, 25, 5, .... Write the rule a_n using the geometric sequence formula:

• a_n = (125)(1/5)^(n-1)

• a_n = 625(1/5)^(n-1)

• a_n = 625(5)^(n-1)

• a_n = 125 + 5n

Find the common ratio for the geometric sequence.

• 10

• 1/2

• 2

• 4

Which of the following is the recursive formula for geometric sequences?

• g_n=g_n-1 (r)

• g_n=g₁ (r^n-1)

Find the next three terms: -4, -12, -36, -108, ...

• 36, -108, 324

• -324, -972, -2916

• 324, -972, 2916

• -108, 324, -972

What two equations that models this sequence?

• t(n) = 10(2)ⁿ

• t(n) = 10(2)^n-1

• t(n) = 5(2)ⁿ

• t(n) = 5(2)^n-1

Find a₁₂ for the geometric sequence defined by the following formula:

a_n = 6(2)^n-1

• 4096

• 24,576

• 2048

• 12,288

What two formulas describe the following geometric sequence: 100, 50, 25, 12.5, ...

• a_n = 2(100)^n-1

• a_n = 200(1/2)ⁿ

• a_n = 100(1/2)^n-1

• a_n = (1/2)(100)ⁿ

Select any statement that is true concerning the sequence 5, 10, 20, 40, 80...

• The sequence is arithmetic

• The sequence is geometric

• The explicit formula is a_n = 5(2)^n-1

• The sequence can be modeled by a linear function.

• The sequence can be modeled by an exponential function.