The sigma notation

IB SL/HL

A Greek letter - in maths it translates as the sum of

start term r=1

end term r=5

the sum of the first 5 terms

What type of series is it?

Make r=1, r=2, ....

r=1, 4-1=3

r=2, 8-1=7r=3, 12-1=11

3, 7, 11, ....

AP: u1=3, d=4, n=5

=55

Find the following information:

1. Type of series (AP or GP)

2. n

3. u1

4. difference (d) or ratio (r)

5. The sum

1. 8, 16, 32, .... a GP

2. n=6 (careful .. use your fingers to count)

3. u1 = 8

4. r = 2

5. 504

Solve each of the following sums

1. GP: 265680

2. AP: 858

3. GP: 1023

4. GP: 286375

5. AP: 102.5

6. AP: 10400