Skip to main content
Ch. 6 - Inverse Circular Functions and Trigonometric Equations
Lial - Trigonometry 12th Edition
Lial12th EditionTrigonometryISBN: 9780136552161, 9780135440780, 9780136881117, 9780135440827, 9780135924891Non è quello che usi tu?Cambia libro di testo
Capitolo 7, Problema 33

Solve each equation for exact solutions.
tan⁻¹ x = cot⁻¹ 7/5

Guida verificata passo dopo passo
1
Recall the relationship between inverse tangent and inverse cotangent functions: \(\tan^{-1} x = \cot^{-1} y\) implies \(x = \frac{1}{y}\), because \(\cot \theta = \frac{1}{\tan \theta}\).
Given the equation \(\tan^{-1} x = \cot^{-1} \frac{7}{5}\), rewrite the right side using the reciprocal relationship: \(\cot^{-1} \frac{7}{5} = \tan^{-1} \frac{5}{7}\).
Set the expressions equal: \(\tan^{-1} x = \tan^{-1} \frac{5}{7}\), which means \(x = \frac{5}{7}\), considering the principal values of inverse tangent.
Remember that inverse tangent and cotangent functions have ranges that might allow for additional solutions differing by \(\pi\), so consider the general solution for \(\tan^{-1} x = \cot^{-1} \frac{7}{5}\) by using the identity \(\cot^{-1} y = \tan^{-1} \frac{1}{y} + k\pi\) for integers \(k\).
Write the general solution as \(x = \tan \left( \cot^{-1} \frac{7}{5} + k\pi \right)\) and simplify to find all exact solutions, where \(k\) is any integer.

Risposta video verificata per un problema simile:

Questa soluzione video è stata consigliata dai nostri tutor come utile per risolvere questo problema.

Concetti chiave

Ecco i concetti essenziali che devi comprendere per rispondere correttamente alla domanda.

Inverse Trigonometric Functions

Inverse trigonometric functions, such as tan⁻¹ (arctan) and cot⁻¹ (arccot), return the angle whose trigonometric ratio equals a given value. Understanding their ranges and how to interpret their outputs is essential for solving equations involving these functions.
Video consigliato:
Percorso guidato
4:28
Introduction to Inverse Trig Functions

Relationship Between Tangent and Cotangent

Tangent and cotangent are reciprocal functions, meaning tan(θ) = 1/cot(θ). This relationship helps convert between tan⁻¹ and cot⁻¹ expressions, allowing the equation to be rewritten in a single trigonometric function for easier solution.
Video consigliato:
Percorso guidato
5:37
Introduction to Cotangent Graph

Exact Solutions and Principal Values

Exact solutions involve finding precise angle values, often expressed in terms of inverse trig functions or special angles. Since inverse trig functions have principal value ranges, recognizing these ranges ensures the correct angle is identified as the solution.
Video consigliato: