Interpreting Function Parameters
Aligned to F-LE.B.5 — Common Core State Standards for Mathematics.
What this lesson teaches
In a model, each number has a real meaning — in y = mx + b, m is the rate of change and b is the starting value; in an exponential a·b^x, a is the start and b is the growth factor.
Worked example
A gym cost is C(x) = 5x + 20. The 5 means each visit costs $5 (the rate), and the 20 is the $20 one-time join fee (the starting value).
Practice questions
- In y = 3x + 50, what do the 3 and the 50 mean if y is total pay?
- In P(x) = 200 × 1.5^x, what does the 200 represent?
- In P(x) = 200 × 1.5^x, what does the 1.5 tell you about growth?
Watch the lesson
Every lesson comes with a video taught in English and Spanish — the same video the QR code in the printed workbook opens.
▶ Watch this lessonEn español
Interpretar los Parámetros de una Función
En un modelo, cada número tiene un significado real: en y = mx + b, m es la tasa de cambio y b es el valor inicial; en una exponencial a·b^x, a es el inicio y b es el factor de crecimiento.
Ejemplo: El costo de un gimnasio es C(x) = 5x + 20. El 5 significa que cada visita cuesta $5 (la tasa), y el 20 es la cuota única de inscripción de $20 (el valor inicial).
More Functions lessons
Teach this lesson today
An AI tutor that guides with questions instead of just giving answers — all K–12 core subjects, every child in the family.
Start free — no card required