geometric sequence review

Is the sequence 2, 4, 12, 48,... geometric?

• yes
• no

What is the common ratio for the sequence:
28, 14, 7, 3.5...

• 2
• 1/2
• -14
• -7

Find the common ratio: 4, -16, 64, -256, ...

• r = -4
• r = 2
• r = -2
• r = 4

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

• 36, -108, 324
• -324, -972, -2916
• 324, -972, 2916
• -108, 324, -972

Which formula is used to find the explicit equation for geometric sequences?

• a_n = a_n-1 + d
• a_n = a_n-1 * r
• a_n = a₁ + d(n-1)
• a_n = a₁ * r^n-1

Which formula is used to find the recursive equation for geometric sequences?

• a_n = a_n-1 + d
• a_n = a_n-1 * r
• a_n = a₁ + d(n-1)
• a_n = a₁ * r^n-1

Find the explicit rule for: 64, -32, 16, -8, …

• 64(1/2)^n-1

• (-32)^n-1

• 64(-1/2)^n-1

• (32)^n-1

Write an explicit rule for the general term of the sequence 5, 15, 45, . . . ?

• a_n = a_n-1 x 3
• a_n = 5(3)^n-1
• a_n = 3(5)^n-1
• a_n = 5 + (n-1)3

Find the 11^th term for:  64, -32, 16, -8, …  

• -.0625
• .0625
• -.03125
• .03125

Choose all of the geometric sequences

• 1, 2, 4, 8, 16,....

• 400, 200, 100, 50, 25,....

• 100, 400, 700, 1000,.....

• 5, -15, 45, -135, ......