Common Core · High school
HSF-BF.A.1.A
High school — Determine an explicit expression, a recursive process, or steps for calculation from a context.
The 2 skills that cover it
- Arithmetic & Geometric SequencesSee a list of numbers as a function of its position: tell an arithmetic sequence from a geometric one, write explicit and recursive formulas, and find any term without listing the ones before it.Read the lesson →
- Piecewise Functions & ModellingBuild the function a situation needs: evaluate and write piecewise and step functions, find the average rate of change on an interval, turn a box, a fence or a price into a polynomial model, choose the right family, and use direct, inverse and joint variation.Read the lesson →
What a student should be able to do
- Identify a sequence as arithmetic or geometric and find its common difference or ratio.
- Write an explicit formula for the nth term and use it to find a given term.
- Write and use a recursive formula, and convert between recursive and explicit forms.
- Find a formula from two given terms.
- Evaluate a piecewise or step function and match a description to its rule.
- Find the average rate of change of a function over an interval from a rule, a table or a graph.
- Build a polynomial or rational model from a described situation and use it to answer a question.
- Choose the function family a situation calls for, interpret its parameters, and solve direct, inverse and joint variation problems.