Common Core
F-IF.A.1
4 lessons teach this standard. Every lesson is interactive, and every one prints as a worksheet with a separate answer key.
Algebra 1 · Chapter 3 · Lesson 1
Function Notation, Domain, and Range
A name for the rule, and the numbers it accepts.
Algebra 1 · Chapter 3 · Lesson 2
One input, one output — never two.
Multivariable Calculus · Chapter 3 · Lesson 1
Two inputs in, one height out.
Differential Equations · Chapter 4 · Lesson 2
When you can trust that an answer exists, and that it is the only one.