Sequences and Series Practice

a_n = a₁ + (n - 1) * d
What formula is this?

• Explicit Arithmetic Formula

• Explicit Geometric Formula

• Arithmetic Series Formula

• Geometric Series Formula

a_n = a₁ * (r)^{n - 1} 
What formula is this?

• Explicit Arithmetic Formula

• Explicit Geometric Formula

• Finite Arithmetic Series Formula

• Finite Geometric Series Formula

S_n = (n/2) (a₁ + a_n)
What formula is this?

• Explicit Arithmetic Formula

• Explicit Geometric Formula

• Finite Arithmetic Series Formula

• Finite Geometric Series Formula

             a₁ * (1 - (r)ⁿ)
S_n =     ------------------
                   1 - r
What formula is this?

• Infinite Arithmetic Series Formula

• Finite Geometric Series Formula

• Finite Arithmetic Series Formula

• Infinite Geometric Series Formula

                    a₁
S_n =     ------------------
                   1 - r
What formula is this?

• Infinite Arithmetic Series Formula

• Finite Geometric Series Formula

• Finite Arithmetic Series Formula

• Infinite Geometric Series Formula

What is the sum of the first ten terms of the sequence 4, -12, 36, -144 . . . ?

• 59,050

• -59,048

• -78,732

• 118,096

Find the sum of the infinite geometric series:

200 - 100 + 50 - 25 + ...

• 525 / 2

• 400 / 3

• 3 / 400

• 2 / 525

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

Find the first four terms of the sequence given the rule:
a_n = 4(5)^n-1

• 20, 100, 500, 2500

• 5, 20, 80, 320

• 4, 20, 100, 500

• 4, 9, 14, 19

Find a₁₂ in the sequence -1, -3, -9, -27, ...

• -177,147

• -19,683

• -59,049

• 118,098