For what values of [tex]\theta \ (0 \leq \theta \leq 2 \pi)[/tex] do maximum [tex]r[/tex]-values occur on the graph of the polar equation [tex]r = -3 + 4 \cos \theta[/tex]? Note that the maximum [tex]r[/tex]-value occurs at a point that is the maximum distance from the pole.

A. [tex]0, \pi[/tex]
B. [tex]0, \frac{\pi}{2}, \pi, \frac{3 \pi}{2}[/tex]
C. 0
D. [tex]\pi[/tex]

Please select the best answer from the choices provided:
A
B
C
D



Answer :

To determine the values of [tex]\(\theta\)[/tex] where the maximum [tex]\(r\)[/tex]-values occur for the given polar equation [tex]\(r = -3 + 4 \cos \theta\)[/tex], we will analyze the equation step-by-step and consider the behavior of [tex]\(\cos \theta\)[/tex].

1. Consider the Range of [tex]\(\cos \theta\)[/tex]:
[tex]\[ \cos \theta \text{ varies between -1 and 1.} \][/tex]

2. Find the expression for [tex]\(r\)[/tex]:
[tex]\[ r = -3 + 4 \cos \theta. \][/tex]

3. Analyze the Conditions for Maximum [tex]\(r\)[/tex]:
[tex]\[ \text{To maximize } r, \text{ we need to maximize } 4 \cos \theta. \][/tex]
[tex]\[ \cos \theta \text{ achieves its maximum value of 1 when } \theta \text{ is } 0\text{ or } 2\pi. \][/tex]

4. Calculate [tex]\(r\)[/tex] at [tex]\(\theta = 0\)[/tex]:
[tex]\[ r = -3 + 4 \cos(0) = -3 + 4 \cdot 1 = 1. \][/tex]
[tex]\[ \theta = 0 \text{ (or } 2\pi \text{ as } \cos(2\pi) = 1 \text{ again)} \text{ gives the maximum value of \(r\).} \][/tex]

So, the maximum [tex]\(r\)[/tex]-value occurs at [tex]\(\theta = 0\)[/tex].

Given the choices:
a. [tex]\(0, \pi\)[/tex]
b. [tex]\(0, \frac{\pi}{2}, \pi, \frac{3 \pi}{2}\)[/tex]
c. [tex]\(0\)[/tex]
d. [tex]\(\pi\)[/tex]

The correct answer is [tex]\(\boxed{C}\)[/tex].