Skip to main content
Ch. 2 - Acute Angles and Right Triangles
Lial - Trigonometry 12th Edition
Lial12th EditionTrigonometryISBN: 9780136552161Not the one you use?Change textbook
Chapter 3, Problem 6

CONCEPT PREVIEW Match each trigonometric function value or angle in Column I with its appropriate approximation in Column II.
Column I: 1.
sec 18°
Column II:
A. 88.09084757°
B. 63.25631605°
C. 1.909152433°
D. 17.45760312°
E. 0.2867453858
F. 1.962610506
G. 14.47751219°
H. 1.015426612
I. 1.051462224
J. 0.9925461516

Verified step by step guidance
1
Step 1: Identify the trigonometric functions or angles given in Column I and understand what each represents. For example, if you have \( \sec 18^\circ \), recall that \( \sec \theta = \frac{1}{\cos \theta} \).
Step 2: Calculate or recall the approximate values of the trigonometric functions for the given angles. For instance, compute \( \sec 18^\circ = \frac{1}{\cos 18^\circ} \) using a calculator or known cosine values.
Step 3: Compare the calculated values with the numerical approximations listed in Column II. Match each function or angle from Column I to the closest numerical value in Column II based on your calculations.
Step 4: For angles listed in Column I without explicit functions, consider if they correspond to inverse trigonometric function results or direct angle measures. Use inverse functions like \( \arcsin, \arccos, \arctan \) if necessary to find angle approximations.
Step 5: Verify each match by checking consistency, such as ensuring that the angle approximations correspond to the correct function values and that the numerical values are within reasonable rounding errors.

Verified video answer for a similar problem:

This video solution was recommended by our tutors as helpful for the problem above.
Video duration:
2m
Was this helpful?

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Trigonometric Functions and Their Values

Trigonometric functions like sine, cosine, tangent, and secant relate angles of a right triangle to ratios of its sides. Understanding how to compute or approximate these values for given angles is essential for matching function values to their numerical approximations.
Recommended video:
6:04
Introduction to Trigonometric Functions

Inverse Trigonometric Functions and Angle Determination

Inverse trigonometric functions allow us to find an angle when given a trigonometric ratio. This concept is crucial for matching numerical values back to their corresponding angles, especially when approximations are involved.
Recommended video:
4:28
Introduction to Inverse Trig Functions

Degree and Radian Measurement and Conversion

Angles can be measured in degrees or radians, and converting between these units is often necessary. Recognizing the unit of the given values and approximations helps correctly interpret and match angles with their trigonometric values.
Recommended video:
5:04
Converting between Degrees & Radians