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 13

Find the exact value of each real number y. Do not use a calculator.
y = arccot (―1)

Guida verificata passo dopo passo
1
Recall the definition of the arccotangent function: \(y = \arccot(x)\) means \(\cot(y) = x\) and \(y\) lies in the principal range of arccot, which is usually \(0 < y < \pi\) for real numbers.
Set up the equation from the problem: \(\cot(y) = -1\).
Recall that \(\cot(y) = \frac{\cos(y)}{\sin(y)}\). So, \(\frac{\cos(y)}{\sin(y)} = -1\) implies \(\cos(y) = -\sin(y)\).
Divide both sides by \(\cos(y)\) (assuming \(\cos(y) \neq 0\)) to get \(1 = -\tan(y)\), or equivalently \(\tan(y) = -1\).
Find the angle \(y\) in the interval \((0, \pi)\) where \(\tan(y) = -1\). This corresponds to the angle where tangent is negative and equals \(-1\).

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 Cotangent Function (arccot)

The arccot function is the inverse of the cotangent function, returning an angle whose cotangent is the given value. It is important to understand its principal value range, typically (0, π), to find the correct angle without ambiguity.
Video consigliato:
Percorso guidato
5:37
Introduction to Cotangent Graph

Cotangent Function and Its Values

Cotangent is defined as the ratio of the adjacent side to the opposite side in a right triangle, or cot(θ) = cos(θ)/sin(θ). Knowing common cotangent values, such as cot(3π/4) = -1, helps in identifying the exact angle corresponding to a given cotangent value.
Video consigliato:
Percorso guidato
5:37
Introduction to Cotangent Graph

Exact Values of Special Angles

Certain angles like π/4, π/3, and π/6 have well-known trigonometric values. Recognizing these special angles and their cotangent values allows for determining exact values without a calculator, which is essential for solving inverse trigonometric problems.
Video consigliato:
Percorso guidato
04:39
45-45-90 Triangles