8 Arithmetic sequences

Question 1

What is significant about arithmetic sequences?

Answer 1

• They have a common difference

- Un= a + (n-1)d

Question 2

What is the sum of an arithmetic sequence?

Answer 2

Sn=(2a+(n-1)d)

Question 3

If they give you the sum to 10 terms = 400 and the sum of the next 10 terms = 1,000 how can you use this?

Answer 3

Create an equation for the sum to the first 10 terms = 400

Create an equation for the sum to the 20 terms =1400

Question 4

If they give you the sum to 10 terms = 400 and the sum of the next 10 terms = 1,000 how can you use this?

Answer 4

Create an equation for the sum to the first 10 terms = 400

Create an equation for the sum to the 20 terms =1400

Question 5

How to answer questions that ask to work out the sum of all the odd numbers/ multiples of a certain number?

Answer 5

• First work out the number of terms using the last term

- Then create a sum with the information given.

Question 6

What is the way to approach arithmetic sequences questions?

Answer 6

-DNA
Difference
Number
A (first)