Page 14 - Math SL HB Sem 1

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SEOUENCE AND SERIES

SIGMA NOTATION

Consider the series I + 2+4+8+ 16+32
As each term is a power ol2 we can write this series in the form

20 +2t +22 +23 +24 +2t and the general term of this seriesis2' .
Using I as a symbol for' the sum of terms' we redefine our series more concisely as

upper
bound
5
\- r' (the sum of lerms ofthe form 2')
/-'
r-2
t_
lower
bound

Example L Write the following series in the sigma notation

(a) I +4+9+ 16 +...+ 100 (b) 1.2+2.3+3.4+...119.20

(c)l -x + x' - x'+... (d)2 4+8-16+...+128

2-2