Sequences

[kelicker]

I have a few questions about sequences in the CCSS associated with Algebra 1 by the PARCC Frameworks.

1. What is the distinction between the following two standards? I find them to be very closely related.

F-IF.A.3 Recognize that sequences are functions, sometimes defined recursively, whose domain is a subset of the integers. For example, the Fibonacci sequence is defined recursively by f(0) = f(1) = 1, f(n+1) = f(n) + f(n-1) for n ≥ 1.

F-BF.A.2 Write arithmetic and geometric sequences both recursively and with an explicit formula, use them to model situations, and translate between the two forms.★

The PARCC “Assessment Limits for Standards Assessed on More Than One End-of-Course Test” states that F-IF.A.3 is “part of the Major work in Algebra I and will be assessed accordingly.” Yet according to the “Pathway Summary Table,” F-BF.A.2 will not be tested in Algebra 1.

2. What notation will be primarily used to represent sequences in Algebra 1? I understand that it is beneficial to expose students to multiple notations, however I have been trying to align my instruction to use the language (and notation) of the standards.

There is a specific notation used in F-IF.A.3, and the Progressions states “In courses that address material corresponding to the plus standards, students may use subscript notation for sequences.” This leads me to infer that the primary notation in Algebra 1 will be as in F-IF.A.3. On the contrary, the PARCC reference sheet provides the formulas using the subscript notation. Will subscript notation appear on the Algebra 1 PARCC exam, or will the PARCC reference sheet be altered for Algebra 1?

I thank you for creating this site and taking time to answer questions.

[Author]

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