Skip to main content
Ch. 6 - Inverse Circular Functions and Trigonometric Equations
Lial - Trigonometry 12th Edition
Lial12th EditionTrigonometryISBN: 9780136552161Not the one you use?Change textbook
Chapter 7, Problem 55

Solve each equation for x.
4/3 arctan x/2 = π

Verified step by step guidance
1
Start by isolating the arctan expression. Multiply both sides of the equation by \( \frac{3}{4} \) to get \( \arctan \left( \frac{x}{2} \right) = \frac{3}{4} \pi \).
Recall that \( \arctan(y) = \theta \) means \( \tan(\theta) = y \). So rewrite the equation as \( \tan \left( \frac{3}{4} \pi \right) = \frac{x}{2} \).
Evaluate \( \tan \left( \frac{3}{4} \pi \right) \) by considering the unit circle or known tangent values at special angles.
Once you find \( \tan \left( \frac{3}{4} \pi \right) \), set it equal to \( \frac{x}{2} \) and solve for \( x \) by multiplying both sides by 2.
Remember to consider the domain and range of the arctan function and check if there are any additional solutions based on the periodicity of the tangent function.

Verified video answer for a similar problem:

This video solution was recommended by our tutors as helpful for the problem above.
Was this helpful?

Key Concepts

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

Inverse Trigonometric Functions (Arctan)

The arctan function is the inverse of the tangent function, returning the angle whose tangent is a given number. It is essential for solving equations where the variable is inside a tangent function, allowing us to isolate the variable by applying arctan to both sides.
Recommended video:
4:28
Introduction to Inverse Trig Functions

Solving Equations Involving Fractions and π

Equations involving fractions and π require careful manipulation of constants and variables. Understanding how to isolate the variable by multiplying or dividing both sides, and recognizing the value of π (approximately 3.1416), is crucial for accurate solutions.
Recommended video:
4:02
Solving Linear Equations with Fractions

Algebraic Manipulation and Isolation of Variables

Algebraic skills are necessary to isolate the variable x after applying inverse functions. This includes multiplying both sides by constants, simplifying expressions, and solving for x step-by-step to find the exact or approximate solution.
Recommended video:
5:28
Equations with Two Variables