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Rates of Change in Polar Functions

Tom Green

Tom Green

7 min read

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Study Guide Overview

This study guide covers rates of change in polar functions, focusing on how to analyze r = f(θ). It explains expanding and contracting polar functions, how to identify relative extrema (maximums and minimums), and calculating the average rate of change. It also includes helpful exam tips and practice questions.

AP Pre-Calculus: Rates of Change in Polar Functions - Night Before Review 🚀

Hey! Let's get you prepped for the exam. This guide is designed to be your quick, go-to resource. We'll break down polar functions, rates of change, and how to tackle those tricky questions. Let's do this! 💪

3.15 Rates of Change in Polar Functions

🔄 Expanding and Contracting Polar Functions

Key Concept

Remember, in polar coordinates, we're dealing with r = f(θ), where r is the distance from the origin and θ is the angle. This is key to understanding how these functions behave. 💡

  • Expanding Polar Function 🌖:
    • If r is positive and increasing as θ increases, the function moves away from the origin.
  • Contracting Polar Function 🌘:
    • If r is negative and decreasing as θ increases, the function moves towards the origin.
Memory Aid

Think of a snail moving along a spiral. If the spiral is moving outwards, it's expanding, if inwards, it's contracting! 🐌

Polar Graph


Caption: Visualizing polar coordinates. The radius 'r' and angle 'θ' define a point's location.

Exam Tip

Pay attention to whether the function is increasing or decreasing. This tells you if the curve is moving towards or away from the origin. This is often tested in multiple choice questions.

🔀 Relative Extrema

  • Relative Extrema: These occur...

Question 1 of 6

If the radius rr of a polar function is positive and increasing as θ\theta increases, what does this indicate about the graph?

The function is contracting towards the origin

The function is expanding away from the origin

The function's radius is constant

The function is oscillating around the origin