/*! 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 19 Derive the following derivative ... [FREE SOLUTION] | 91Ó°ÊÓ

91Ó°ÊÓ

Derive the following derivative formulas given that \(d / d x(\cosh x)=\sinh x\) and \(d / d x(\sinh x)=\cosh x\). \(d / d x(\operatorname{coth} x)=-\operatorname{csch}^{2} x\)

Short Answer

Expert verified
Answer: The derivative of \(\coth x\) is \(-\operatorname{csch}^2 x\).

Step by step solution

01

Recall the Quotient Rule

The Quotient Rule states that the derivative of a quotient of two functions is given by: \(\frac{d}{dx}\left(\frac{u(x)}{v(x)}\right) = \frac{u'(x) v(x) - u(x) v'(x)}{[v(x)]^2}\)
02

Apply the Quotient Rule to \(\coth x\)

Following the Quotient Rule, let \(u(x) = \cosh x\) and \(v(x) = \sinh x\). Thus, we have: \(\frac{d}{dx}(\coth x) = \frac{d}{dx}\left(\frac{\cosh x}{\sinh x}\right) = \frac{u'(x) v(x) - u(x) v'(x)}{[v(x)]^2}\)
03

Substitute the given formulas for the derivatives

Now, remember the formulas for the derivatives of \(\cosh x\) and \(\sinh x\): \(d / d x(\cosh x)=\sinh x\) and \(d / d x(\sinh x)=\cosh x\). Replace \(u'(x)\) with \(\sinh x\) and \(v'(x)\) with \(\cosh x\) in the expression above. \(\frac{d}{dx}(\coth x) = \frac{(\sinh x)(\sinh x) - (\cosh x)(\cosh x)}{[\sinh x]^2}\)
04

Simplify the expression

Now, we have to simplify the expression. We will use the identity \(\cosh^2 x - \sinh^2 x = 1\). Thus, the expression becomes: \(\frac{d}{dx}(\coth x) = \frac{1 - \cosh^2 x}{\sinh^2 x}\)
05

Rewrite using the definition of \(\operatorname{csch}\)

Finally, we can rewrite the expression using the definition of \(\operatorname{csch}\), which is \(\operatorname{csch} x = \frac{1}{\sinh x}\). Our expression becomes: \(\frac{d}{dx}(\coth x) = -\operatorname{csch}^2 x\) Thus, we have derived the formula for the derivative of \(\coth x\): \(d / d x(\coth x)=-\operatorname{csch}^2 x\).

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.

Derivatives
In calculus, a derivative represents the rate at which a function is changing at any given point. It is a fundamental concept that shows how one quantity changes with respect to another. In simple terms, if you think of a graph, the derivative at a point is the slope of the tangent line at that point.

Understanding derivatives is crucial because they can help solve real-world problems such as predicting population growth or determining the optimum speed for efficiency. When dealing with functions, especially more complex ones like hyperbolic functions, derivatives allow us to explore these ideas further and analyze behavior.
  • Derivatives express rates of change.
  • They help determine slope and behavior of functions.
  • They are used in various fields for optimization and prediction.
Hyperbolic Functions
Hyperbolic functions are similar to trigonometric functions but are based on hyperbolas instead of circles. The main hyperbolic functions are sinh (hyperbolic sine), cosh (hyperbolic cosine), and tanh (hyperbolic tangent). They are defined with exponential functions and appear in many mathematical contexts, especially in calculus.

With hyperbolic functions, it's important to know their derivatives:
  • The derivative of \(\cosh x\) is \(\sinh x\).
  • The derivative of \(\sinh x\) is \(\cosh x\).
These derivatives are highly useful in solving calculus problems that involve hyperbolic functions. They have unique properties and applications in engineering, physics, and hyperbolic geometry.

Hyperbolic functions offer an alternative to trigonometric functions in certain scenarios, where their geometric interpretation based on hyperbolas can be more suitable.
  • Hyperbolic functions are derived from hyperbolas.
  • They include sinh, cosh, and tanh.
  • Commonly used in advanced calculus and applied sciences.
Quotient Rule
The quotient rule is a method for finding the derivative of a function that is the quotient of two other functions. It's especially useful when dealing with ratios or divisions in calculus. The rule states that if you have a function \(\frac{u(x)}{v(x)}\), then its derivative can be found using:

\[\frac{d}{dx}\left(\frac{u(x)}{v(x)}\right) = \frac{u'(x) v(x) - u(x) v'(x)}{[v(x)]^2}\]
This formula is key when working specifically with expressions like \(\coth x\), as it involves a division of hyperbolic sine and cosine functions.
When applying the quotient rule:
  • Select \(u(x)\) and \(v(x)\) appropriately based on the function's structure.
  • Compute \(u'(x)\) and \(v'(x)\).
  • Ensure to substitute these derivatives correctly into the formula.
For example, in deriving \(\frac{d}{dx}(\coth x)\), the quotient rule helps simplify and solve for the derivative efficiently by organizing complex expressions into manageable steps.
  • The quotient rule is vital for derivatives involving division.
  • It requires clear differentiation of the numerator and denominator functions.
  • Important for simplifying complex calculus problems.

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

Devise the exponential growth function that fits the given data; then answer the accompanying questions. Be sure to identify the reference point\((t=0)\) and units of time. The current population of a town is 50,000 and is growing exponentially. If the population is projected to be 55,000 in 10 years, then what will be the population 20 years from now?

Let \(R\) be the region bounded by the following curves. Use the shell method to find the volume of the solid generated when \(R\) is revolved about the \(y\) -axis. $$y=\sqrt{x}, y=0, \text { and } x=4$$

Use the general slicing method to find the volume of the following solids. The solid with a semicircular base of radius 5 whose cross sections perpendicular to the base and parallel to the diameter are squares

Archimedes' principle says that the buoyant force exerted on an object that is (partially or totally) submerged in water is equal to the weight of the water displaced by the object (see figure). Let \(\rho_{w}=1 \mathrm{g} / \mathrm{cm}^{3}=1000 \mathrm{kg} / \mathrm{m}^{3}\) be the density of water and let \(\rho\) be the density of an object in water. Let \(f=\rho / \rho_{w}\). If \(01,\) then the object sinks. Consider a cubical box with sides 2 m long floating in water with one-half of its volume submerged \(\left(\rho=\rho_{w} / 2\right) .\) Find the force required to fully submerge the box (so its top surface is at the water level).

Suppose a force of \(15 \mathrm{N}\) is required to stretch and hold a spring \(0.25 \mathrm{m}\) from its equilibrium position. a. Assuming the spring obeys Hooke's law, find the spring constant \(k\) b. How much work is required to compress the spring \(0.2 \mathrm{m}\) from its equilibrium position? c. How much additional work is required to stretch the spring \(0.3 \mathrm{m}\) if it has already been stretched \(0.25 \mathrm{m}\) from its equilibrium position?

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.