Series & Sequence Review

Write the first FOUR terms for the sequence shown here. DO NOT PUT SPACES, PUT COMMAS IN BETWEEN

Answer explanation

They gave you the first term and the RECURSIVE formula. It tells you what to do with the PREVIOUS term.

Tags

CCSS.HSF.BF.A.2

Give me the first THREE terms for the sequence shown here. Again, no spaces just commas.

Answer explanation

This one doesn't say a sub n-1. You just plug in the term number.

Tags

CCSS.HSF.BF.A.2

Find the explicit formula for the sequence: -16, -4, -1, -1/4, -1/16

• an = an-1/4

• an = 4n - 20

• an = -16(4)^n-1

• an = -16(1/4)^n-1

Answer explanation

Recursive formulas are the ones that use a sub n-1. Otherwise, If you're adding/subtracting you do: an = a1 +d(n-1) and simplify. If it's multiplying/dividing: an = a1(r)^n-1 Remember if you're dividing that multiplying by a fraction.

Tags

CCSS.HSF.BF.A.2

Find the explicit formula for the sequence: -2, 4, 10, 16, ...

• an = an-1 + 6

• an = 6n - 8

• an =6n + 4

• an = -2(6)^n-1

Answer explanation

Recursive formulas are the ones that use a sub n-1. Otherwise, If you're adding/subtracting you do: an = a1 +d(n-1) and simplify. If it's multiplying/dividing: an = a1(r)^n-1 Remember if you're dividing that multiplying by a fraction.

Tags

CCSS.HSF.BF.A.2

You said the formula was an= 6n - 8. Find a17

Answer explanation

Recursive formulas are the ones that use a sub n-1. Otherwise, If you're adding/subtracting you do: an = a1 +d(n-1) and simplify. If it's multiplying/dividing: an = a1(r)^n-1 Remember if you're dividing that multiplying by a fraction.

Tags

CCSS.HSF.BF.A.2

List the next 2 numbers in the sequence (no spaces, just commas)

Tags

CCSS.HSF.BF.A.2

Which of these correctly writes the series shown in summation notation: 5+9+13+17+21

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Answer explanation

K =1 and then the top number should be the number of terms. The expression next to the sigma should be the explicit formula that yields the numbers you see in the series.

Tags

CCSS.HSF.BF.A.2

Which of these correctly writes the series shown in summation notation: 7 - 14 + 28 - 56

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Answer explanation

K =1 and then the top number should be the number of terms. The expression next to the sigma should be the explicit formula that yields the numbers you see in the series.

Tags

CCSS.HSF.BF.A.2

Evaluate

Answer explanation

The formula when it's a constant is nc.

When it's a linear series (k) it's n(n+1)/2

When it's a quadratic series (k^2) it's n(n+1)(2n+1)/6

Evaluate