Find the exact value of the trig function. Don't forget to rationalize any denominators. Sec 945° mono

Trigonometry (MindTap Course List)
8th Edition
ISBN:9781305652224
Author:Charles P. McKeague, Mark D. Turner
Publisher:Charles P. McKeague, Mark D. Turner
Chapter2: Right Triangle Trigonometry
Section: Chapter Questions
Problem 5GP
icon
Related questions
Question
**Finding the Exact Value of the Trigonometric Function**

Ensure to rationalize any denominators.

**Problem Statement:**

Find the exact value of the trigonometric function.
Don't forget to rationalize any denominators.

**Trigonometric Function:**
\[ \sec 945^\circ \]

**Solution:**

To find the exact value of \(\sec 945^\circ\):

1. **Reduce the Angle:**
   The angle given, \(945^\circ\), is more than one full circle (360°). First, we reduce \(945^\circ\) by finding the equivalent angle between \(0^\circ\) and \(360^\circ\):
   \[
   945^\circ - 2 \times 360^\circ = 945^\circ - 720^\circ = 225^\circ 
   \]

2. **Identify Reference Angle:**
   The equivalent angle within one cycle (0° to 360°) is \(225^\circ\). \(225^\circ\) is in the third quadrant where both sine and cosine values are negative.

3. **Secant Function:**
   The secant function is the reciprocal of the cosine function:
   \[
   \sec \theta = \frac{1}{\cos \theta}
   \]

4. **Cosine of 225°:**
   From the unit circle, the cosine of 225° (or \(\cos 225^\circ\)):
   \[
   \cos 225^\circ = -\frac{\sqrt{2}}{2}
   \]

5. **Calculate Secant:**
   Taking the reciprocal of \(\cos 225^\circ\):
   \[
   \sec 225^\circ = \frac{1}{\cos 225^\circ} = \frac{1}{-\frac{\sqrt{2}}{2}} = -\frac{2}{\sqrt{2}}
   \]

6. **Rationalize the Denominator:**
   To rationalize the denominator:
   \[
   -\frac{2}{\sqrt{2}} \times \frac{\sqrt{2}}{\sqrt{2}} = -\frac{2\sqrt{2}}{2} = -\sqrt{2}
   \]

Thus, the exact value of \(\sec 945^\circ\) is:
\[ \boxed{-\sqrt{2}} \
Transcribed Image Text:**Finding the Exact Value of the Trigonometric Function** Ensure to rationalize any denominators. **Problem Statement:** Find the exact value of the trigonometric function. Don't forget to rationalize any denominators. **Trigonometric Function:** \[ \sec 945^\circ \] **Solution:** To find the exact value of \(\sec 945^\circ\): 1. **Reduce the Angle:** The angle given, \(945^\circ\), is more than one full circle (360°). First, we reduce \(945^\circ\) by finding the equivalent angle between \(0^\circ\) and \(360^\circ\): \[ 945^\circ - 2 \times 360^\circ = 945^\circ - 720^\circ = 225^\circ \] 2. **Identify Reference Angle:** The equivalent angle within one cycle (0° to 360°) is \(225^\circ\). \(225^\circ\) is in the third quadrant where both sine and cosine values are negative. 3. **Secant Function:** The secant function is the reciprocal of the cosine function: \[ \sec \theta = \frac{1}{\cos \theta} \] 4. **Cosine of 225°:** From the unit circle, the cosine of 225° (or \(\cos 225^\circ\)): \[ \cos 225^\circ = -\frac{\sqrt{2}}{2} \] 5. **Calculate Secant:** Taking the reciprocal of \(\cos 225^\circ\): \[ \sec 225^\circ = \frac{1}{\cos 225^\circ} = \frac{1}{-\frac{\sqrt{2}}{2}} = -\frac{2}{\sqrt{2}} \] 6. **Rationalize the Denominator:** To rationalize the denominator: \[ -\frac{2}{\sqrt{2}} \times \frac{\sqrt{2}}{\sqrt{2}} = -\frac{2\sqrt{2}}{2} = -\sqrt{2} \] Thus, the exact value of \(\sec 945^\circ\) is: \[ \boxed{-\sqrt{2}} \
Expert Solution
trending now

Trending now

This is a popular solution!

steps

Step by step

Solved in 3 steps with 3 images

Blurred answer
Similar questions
Recommended textbooks for you
Trigonometry (MindTap Course List)
Trigonometry (MindTap Course List)
Trigonometry
ISBN:
9781305652224
Author:
Charles P. McKeague, Mark D. Turner
Publisher:
Cengage Learning