/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none} Problem 89 Verify that equation is an ident... [FREE SOLUTION] | 91Ó°ÊÓ

91Ó°ÊÓ

Verify that equation is an identity. \(\frac{\cos \theta}{\sin \theta \cot \theta}=1\)

Short Answer

Expert verified
Yes, the equation is an identity.

Step by step solution

01

Understand the Equation

We are given the equation \( \frac{\cos \theta}{\sin \theta \cot \theta}=1 \). Our task is to verify whether this equation is an identity, which means it must hold for all permissible values of \( \theta \).
02

Simplify the Expression

Recall that \( \cot \theta = \frac{\cos \theta}{\sin \theta} \). Substitute this into the equation: \( \frac{\cos \theta}{\sin \theta \cdot \frac{\cos \theta}{\sin \theta}} \).
03

Resolve the Denominator

Simplify the expression in the denominator: \( \sin \theta \cdot \frac{\cos \theta}{\sin \theta} = \cos \theta \). Thus the equation becomes \( \frac{\cos \theta}{\cos \theta} \).
04

Simplify the Fraction

The fraction \( \frac{\cos \theta}{\cos \theta} \) simplifies to 1 (provided \( \cos \theta eq 0 \)).
05

Verify the Identity

We have shown that \( \frac{\cos \theta}{\sin \theta \cot \theta} = 1 \) simplifies correctly to 1. Therefore, the original equation is an identity for all values of \( \theta \) where \( \cos \theta eq 0 \).

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Over 30 million students worldwide already upgrade their learning with 91Ó°ÊÓ!

Key Concepts

These are the key concepts you need to understand to accurately answer the question.

Simplification
Simplifying expressions in trigonometry is a crucial skill that helps us understand equations more clearly and reach the solution efficiently. In our exercise,the first step is to simplify the given expression \(\frac{\cos \theta}{\sin \theta \cot \theta}=1\). Understanding how each trigonometric function relates to others enables us to manipulate the equation easily.
To start, recognize the trigonometric identity for the cotangent: \(\cot \theta = \frac{\cos \theta}{\sin \theta}\). By substituting this identity into the denominator of our exercise, the expression becomes easier to navigate through:
  • Convert \(\sin \theta \cdot \cot \theta\) to \(\sin \theta \cdot \frac{\cos \theta}{\sin \theta}\).
  • Simplify the multiplication, noticing that \(\sin \theta\) cancels out with \(\sin \theta\) in the denominator, leaving you with \(\cos \theta\).
By simplifying, you change the equation to \(\frac{\cos \theta}{\cos \theta}\), which directly reduces to 1, ensuring that the equation holds true.
Cotangent
The cotangent function is one of the six fundamental trigonometric functions, often abbreviated as \(\cot\). It constitutes a reciprocal relationship with another function.
Specifically, \(\cot \theta\) is defined as the reciprocal of the tangent function, which means \(\cot \theta = \frac{1}{\tan \theta}\). In terms of sine and cosine, the relationship becomes \(\cot \theta = \frac{\cos \theta}{\sin \theta}\). This identity is particularly useful in solving trigonometric equations, especially those involving products or fractions.
When dealing with trigonometric expressions, converting cotangent using its identity often simplifies complex relationships. You use this identity to simplify expressions like the one in the exercise, breaking down terms into simpler components that are easier to work with.
Verifying Identities
Verifying trigonometric identities involves demonstrating that two sides of an equation are equivalent. This means showing that the equation is true for all values within its domain. In the given exercise, we started with the expression \(\frac{\cos \theta}{\sin \theta \cot \theta}=1\) and simplified it to verify its identity.
The verification process often involves:
  • Using known identities, such as \(\cot \theta = \frac{\cos \theta}{\sin \theta}\), to transform parts of the equation.
  • Simplifying the expression step by step, ensuring each step is backed by logical trigonometric relationships.
  • Confirming that the final simplified form of the equation is equivalent to a universal truth, such as 1 or another simple trigonometric result.
In the end, we've confirmed that our original equation holds as a true identity across allowable values of \(\theta\), thus successfully verifying its correctness.

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

Determining Wattage Amperage is a measure of the amount of electricity that is moving through a circuit, while voltage is a measure of the force pushing the electricity. The wattage \(W\) consumed by an electrical device can be determined by calculating the product of amperage \(I\) and voltage \(V .\) (Source: Wilcox, G. and C. Hesselberth, Electricity for Engineering Technology, Allyn \& Bacon.) (a) A household circuit has voltage $$V=163 \sin 120 \pi t$$ when an incandescent light bulb is turned on with amperage $$I=1.23 \sin 120 \pi t$$ Graph the wattage $$W=V I$$ that is consumed by the light bulb over the interval \(0 \leq t \leq 0.05\) (b) Determine the maximum and minimum wattages used by the light bulb. (c) Use identities to find values for \(a, c,\) and \(\omega\) so that $$ W=a \cos \omega t+c $$ (d) Check your answer in part (c) by graphing both expressions for \(W\) on the same coordinate axes. (e) Use the graph from part (a) to estimate the average watt. age used by the light. How many watts do you think this incandescent light bulb is rated for?

Sound Waves Sound is a result of waves applying pressure to a person's eardrum. For a pure sound wave radiating outward in a spherical shape, the trigonometric function $$P=\frac{a}{r} \cos \left(\frac{2 \pi r}{\lambda}-c t\right)$$ can be used to model the sound pressure \(P\) at a radius of \(r\) feet from the source, where \(t\) is time in seconds, \(\lambda\) is length of the sound wave in feet, \(c\) is speed of sound in feet per second, and \(a\) is maximum sound pressure at the source measured in pounds per square foot. (Source: Beranek, L.., Noise and Vibration Control, Institute of Noise Control Engineering. Washington, DC.) Let \(\lambda=4.9\) feet and \(c=1026\) feet per second. (IMAGE CANNOT COPY) (a) Let \(a=0.4\) pound per square foot. Graph the sound pressure at a distance \(r=10\) feet from its source over the interval \(0 \leq t \leq 0.05 .\) Describe \(P\) at this distance. (b) Now let \(a=3\) and \(t=10 .\) Graph the sound pressure for \(0 \leq r \leq 20 .\) What happens to the pressure \(P\) as the radius \(r\) increases? (c) Suppose a person stands at a radius \(r\) so that $$r=n \lambda$$ where \(n\) is a positive integer. Use the difference identity for cosine to simplify \(P\) in this situation.

Write each expression as an algebraic expression in \(u, u>0\). $$\tan (\arccos u)$$

Give the exact real number value of each expression. Do not use a calculator. $$\tan \left(\tan ^{-1} \frac{3}{4}+\tan ^{-1} \frac{12}{5}\right)$$

Verify that each equation is an identity by using any of the identities introduced in the first three sections of this chapter. $$\frac{\csc t+1}{\csc t-1}=(\sec t+\tan t)^{2}$$

See all solutions

Recommended explanations on Math Textbooks

View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.