Arithmetic Sequences and Explicit Formula

What is the 38th term of this arithmetic sequence? {26, 22, 18, 14, ... }

• -4

• 10

• -122

• 174

Tags

CCSS.HSF.BF.A.2

What is: A list of numbers that increase or decrease by a constant rate

• Geometric sequence

• positive sequence

• negative sequence

• Arithmetic sequences

Tags

CCSS.HSF.BF.A.2

Now we are going to find the value of larger terms:

Find the 10 term of the given sequence

a_n = 4n +2

• 38

• 42

• -42

• 16

Answer explanation

This one is way easier than it sounds:

a(10) = 4(10) + 2

= 40+2

= 42

Tags

CCSS.HSF.BF.A.2

This is an arithmetic sequence and it shows you

a_0 a_1 and a_2

What is the explicit formula?

• a_n = 4n + 1

• a_n = n + 4

• a_n = 4n - 1

• a_n = 5n +1

Tags

CCSS.HSF.BF.A.2

Is this an arithmetic sequence?

• Maybe

• Yes

• No

Answer explanation

The rate is not constant, which is required in arithmetic sequences.

So no, its not arithmetic

Tags

CCSS.HSF.BF.A.2

What two things do you need to write the explicit formula? (Choose two and look carefully)

• the last term

• The zero term (when x=0)

• Constant rate

• changing rate

Answer explanation

You need to find the rate of how the y's change, and then find the f(x) value when x is zero.

Tags

CCSS.HSF.BF.A.2

What is the rate of this arithmetic sequence?

• -2

• 2

• 1

• 14

Tags

CCSS.HSF.BF.A.2

What is the zero term (a_0) of this arithmetic sequence? (hint**you have to find it)

• -2

• -1

• 1

• -2

Tags

CCSS.HSF.BF.A.2

Now we know: zero term= -1 Constant rate= 2 Which explicit formula fits this scenario?

• a_n = -1n + 2

• a_n = 2n - 1

• a_n = n - 1

• a_n = 2n + 1

Tags

CCSS.HSF.BF.A.2

What is the explicit formula for a sequence with a zero term of 6 and a common difference of 3.2?

• a_n = 6n - 3.2

• a_n = 3.2n - 6

• a_n = 3.2n +6

Tags

CCSS.HSF.BF.A.2