/*! 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 9 In Exercises \(1-12,\) find \(d ... [FREE SOLUTION] | 91Ó°ÊÓ

91Ó°ÊÓ

In Exercises \(1-12,\) find \(d y / d x\) $$ y=\frac{4}{\cos x}+\frac{1}{\tan x} $$

Short Answer

Expert verified
\( \frac{dy}{dx} = 4\sec x \tan x - \csc^2 x \).

Step by step solution

01

Identify the Components of the Function

The given function is composed of several trigonometric terms. It can be broken down into two parts: \( \frac{4}{\cos x} \) and \( \frac{1}{\tan x} \). These expressions can be rewritten for easier differentiation using trigonometric identities: \( \frac{4}{\cos x} = 4\sec x \) and \( \frac{1}{\tan x} = \cot x \). Thus, the function can be rewritten as \( y = 4\sec x + \cot x \).
02

Differentiate the Components Separately

To find \( \frac{dy}{dx} \), take the derivative of each component of the function with respect to \( x \). The derivative of \( 4\sec x \) is computed using the chain rule: \( \frac{d}{dx}[4\sec x] = 4\sec x \tan x \). The derivative of \( \cot x \) is \( \frac{d}{dx}[\cot x] = -\csc^2 x \).
03

Combine the Derivatives

Since the derivative of a sum is the sum of the derivatives, add the derivatives of each trigonometric component together to find \( \frac{dy}{dx} \). Thus, \( \frac{dy}{dx} = 4\sec x \tan x - \csc^2 x \).
04

Simplify if Possible

After obtaining \( \frac{dy}{dx} = 4\sec x \tan x - \csc^2 x \), check if the expression can be simplified further. In this case, the expression is in its simplest form using common trigonometric derivatives and operations.

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.

Trigonometric Functions
Trigonometric functions are vital in calculus, especially in problems involving periodic phenomena. In this exercise, we encounter secant (\(\sec x\)) and cotangent (\(\cot x\)). Understanding these functions is crucial. - **Secant Function**: The secant of an angle is the reciprocal of the cosine function: \(\sec x = \frac{1}{\cos x}\). It reveals how the angle relates to a right triangle's hypotenuse and adjacent side.- **Cotangent Function**: The cotangent of an angle is the reciprocal of the tangent function: \(\cot x = \frac{1}{\tan x}\), representing the ratio of the adjacent side to the opposite side of a right triangle.These functions, alongside other trigonometric functions like sine and tangent, are used in a variety of applications including wave analysis and circular motion.
Derivative Rules
To differentiate functions, we apply derivative rules. These rules simplify the process by identifying patterns and applying known formulas. Two primary rules used here are the sum rule and basic trigonometric derivatives.- **Sum Rule**: The derivative of a sum of functions is the sum of their derivatives. For \(y = 4\sec x + \cot x\), differentiate each term individually and add the results.For trigonometric derivatives, well-known formulas include:- **Derivative of \(\sec x\)**: The derivative is \(\sec x \tan x\).- **Derivative of \(\cot x\)**: The derivative is \(-\csc^2 x\). Applying these rules allows us to find the derivative \(\frac{dy}{dx}\) systematically by addressing each term separately.
Chain Rule
The chain rule is essential when differentiating composite functions, and it is particularly important for functions involving multiple layers like secant or tangent functions. It states that the derivative of a composite function \(f(g(x))\) is \(f'(g(x)) \cdot g'(x)\).Here, when differentiating \(4\sec x\), we recognize it as a composition of the constant factor 4 and \(\sec x\), where the chain rule is applied in its basic form by simply following known derivatives. Though trivial in this context, the chain rule's true power comes in more complex nested functions.Always identify inner functions, differentiate each layer systematically, and multiply the results to ensure accuracy.
Secant and Tangent Functions
Secant and tangent functions play a crucial role in this calculus problem. Each has unique properties and derivatives that simplify the problem-solving process.- **Secant Function**: The secant function, \(\sec x\), is important due to its link with the cosine. Its derivative \(\sec x \tan x\) reflects how rapidly the secant function changes. - **Tangent Function**: Although \(\tan x\) itself is not directly part of the given function, its relationship through \(\cot x = \frac{1}{\tan x}\) is relevant. The identity \( \sec^2 x = 1 + \tan^2 x \) showcases the interconnected nature used in verifying derivatives.Understanding these relationships is essential when solving calculus problems, ensuring each derivative is computed correctly. These functions and their properties help form the building blocks of more advanced trigonometric calculus.

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

Tangents parallel to the coordinate axes Find points on the curve \(x^{2}+x y+y^{2}=7\) (a) where the tangent is parallel to the \(x\) -axis and (b) where the tangent is parallel to the \(y\) -axis. In the latter case, \(d y / d x\) is not defined, but \(d x / d y\) is. What value does \(d x / d y\) have at these points?

In Exercises \(37-42,\) write a differential formula that estimates the given change in volume or surface area. The change in the lateral surface area \(S=\pi r \sqrt{r^{2}+h^{2}}\) of a right circular cone when the radius changes from \(r_{0}\) to \(r_{0}+d r\) and the height does not change

Sketching the change in a cube's volume The volume \(V=x^{3}\) of a cube with edges of length \(x\) increases by an amount \(\Delta V\) when \(x\) increases by an amount \(\Delta x\) . Show with a sketch how to represent \(\Delta V\) geometrically as the sum of the volumes of a. three slabs of dimensions \(x\) by \(x\) by \(\Delta x\) b. three slars of dimensions \(x\) by \(\Delta x\) by \(\Delta x\) c. one cube of dimensions \(\Delta x\) by \(\Delta x\) by \(\Delta x\) . The differential formula \(d V=3 x^{2} d x\) estimates the change in \(V\) with the three slabs.

The cissoid of Diocles (from about 200 B.C.) Find equations for the tangent and normal to the cissoid of Diocles \(y^{2}(2-x)=x^{3}\) at \((1,1) .\)

In Exercises \(67-70\) , use a CAS to estimate the magnitude of the error in using the linearization in place of the function over a specified interval \(I\) . Perform the following steps: a. Plot the function \(f\) over \(I .\) b. Find the linearization \(L\) of the function at the point \(a\) . c. Plot \(f\) and \(L\) together on a single graph. d. Plot the absolute error \(|f(x)-L(x)|\) over \(I\) and find its maximum value. e. From your graph in part (d), estimate as large a \(\delta > 0\) as you can, satisfying $$ |x-a|<\delta \quad \Rightarrow \quad|f(x)-L(x)|<\epsilon $$ for \(\epsilon=0.5,0.1,\) and 0.01 . Then check graphically to see if your \(\delta\) -estimate holds true. $$ f(x)=\sqrt{x}-\sin x, \quad[0,2 \pi], \quad a=2 $$

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.