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Nonlinear functions

Brian Hall

Brian Hall

7 min read

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Study Guide Overview

This guide covers nonlinear functions for the AP SAT (Digital) Math exam, focusing on exponential functions (growth/decay, real-world applications), quadratic functions (graph characteristics, solving equations, discriminant), polynomial functions (properties, end behavior, zeros), and rational functions (characteristics, asymptotes, solving equations). It includes example problems and emphasizes key formulas and concepts.

๐Ÿš€ AP SAT (Digital) Math: Nonlinear Functions - Your Night-Before Guide ๐Ÿš€

Hey there! Feeling the pre-exam jitters? No sweat! This guide is your express ticket to mastering nonlinear functions. We'll break down everything you need to know, focusing on what's most likely to show up on the test. Let's make sure you're feeling confident and ready to crush it! ๐Ÿ’ช

๐Ÿ“ˆ Exponential Functions

Basic Structure and Properties

  • General Form: f(x) = a โ‹… bหฃ
    • a = initial value
    • b = base (growth factor)
  • Key Feature: The graph never crosses the x-axis. ๐Ÿšซ
  • Y-intercept: Always equals the initial value a. ๐Ÿ“
  • Rate of Change: Constant percent change over equal intervals. ๐Ÿ”„
Memory Aid

Remember: "a" is where we are, and "b" is how we grow!

Growth and Decay Behavior

  • Growth: b > 1 (function increases rapidly). ๐Ÿš€
  • Decay: 0 < b < 1 (function approaches zero asymptotically). ๐Ÿ“‰
Exponential Growth and Decay Graphs

Exponential growth (left) and decay (right) graphs. Note how growth increases rapidly, while decay approaches zero.

๐Ÿ’ฐ Exponential Growth and Decay

Modeling Real-World Scenarios

  • Equations:
    • A(t) = Aโ‚€ โ‹… (1 + r)แต—
    • A(t) = Aโ‚€ โ‹… eสณแต—
    • Aโ‚€ = initial amount
    • r = growth/decay rate
    • t = time
  • Doubling Time/Half-Life: t = ln(2) / ln(1 + r)
  • Applications: Population growth, radioactive decay, compound interest. ๐ŸŒ

Financial Applications

  • Continuously Compounded Interest: A(t) = P โ‹… eสณแต—
    • P = principal amount
    • r = annual interest rate
    • t = time in years
  • Use: Financial planning, investments, loans. ๐Ÿฆ
Exam Tip

Remember the 'PERT' formula A = Peสณแต— for continuous growth! It's a common application on the exam. ๐Ÿ’ก

๐Ÿงฎ Key Features of Quadratic Graphs

Parabola Characteristics

  • General Form: f(x) = axยฒ + bx + c, where a โ‰  0
  • Graph: A parabola (U-shaped curve). -...

Question 1 of 17

What is the initial value in the exponential function f(x)=5โˆ—(2)xf(x) = 5 * (2)^x?

2

5

10

0