6-3-6

Recursive and Explicit Form of a Sequence

Example: To obtain the n-th terms of a system of recursion formulas an+1 = 3an + bn, bn+1 = an + 3bn with the initial conditions a1 =2, b1 = 1

Calculating the Sum of a Sequence

Perform the following steps when you want to determine the sum of a specific range of the sequence of a recursion expression or a general term expression.

Example: To calculate the sum of the general term expression anE = n2 + 2n – 1 in the range of 2 < n < 10

uClassPad Operation

(1)Start up the Sequence Editor.

If you have another application running, tap mand then H.

If you have the Sequence application running, tap Oand then [Sequence Editor].

(2)Tap (or press) O, [Sequence RUN], [Calc], [Σ], [n,an], [n], e, 2, f, 1, 0, e, [n,an], [n], {, 2, +, 2, [n,an], [n], -, 1.

(3)Press E.

Tip

• For information about the syntax of the “Σ” function, see “2-8 Using the Action Menu”.

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