/*! 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 106 Use the definitions of increasin... [FREE SOLUTION] | 91Ó°ÊÓ

91Ó°ÊÓ

Use the definitions of increasing and decreasing functions to prove that \(f(x)=x^{3}\) is increasing on \((-\infty, \infty)\).

Short Answer

Expert verified
The function \(f(x)=x^{3}\) is increasing on \((-\infty, \infty)\), because its derivative \(3x^2\) is positive for all \(x\).

Step by step solution

01

Calculating the Derivative

First, calculate the derivative of the function \(f(x) = x^3\). The derivative \(f'(x)\) is given by \(3x^2\).
02

Analyzing the Sign of the Derivative

Next, analyze the sign of the derivative. For all \(x\) in the domain \(-\infty < x < \infty\), \(3x^2\) is positive because the square of any real number is positive.
03

Making Conclusions

Since the derivative \(f'(x) = 3x^2\) is defined and positive for all \(x\), it can be concluded that the function \(f(x) = x^3\) is increasing over the interval \((- \infty, \infty)\).

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!

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

In Exercises \(57-74\), sketch the graph of the equation. Look for extrema, intercepts, symmetry, and asymptotes as necessary. Use a graphing utility to verify your result. $$ y=\frac{2 x}{1-x} $$

Consider a fuel distribution center located at the origin of the rectangular coordinate system (units in miles; see figures). The center supplies three factories with coordinates \((4,1),(5,6),\) and \((10,3) .\) A trunk line will run from the distribution center along the line \(y=m x,\) and feeder lines will run to the three factories. The objective is to find \(m\) such that the lengths of the feeder lines are minimized. Minimize the sum of the absolute values of the lengths of vertical feeder lines given by \(S_{2}=|4 m-1|+|5 m-6|+|10 m-3|\) Find the equation for the trunk line by this method and then determine the sum of the lengths of the feeder lines.

Timber Yield The yield \(V\) (in millions of cubic feet per acre) for a stand of timber at age \(t\) (in years) is \(V=7.1 e^{(-48.1) / t}\) (a) Find the limiting volume of wood per acre as \(t\) approaches infinity. (b) Find the rates at which the yield is changing when \(t=20\) years and \(t=60\) years.

Assume that \(f\) is differentiable for all \(x\). The signs of \(f^{\prime}\) are as follows. \(f^{\prime}(x)>0\) on \((-\infty,-4)\) \(f^{\prime}(x)<0\) on (-4,6) \(f^{\prime}(x)>0\) on \((6, \infty)\) Supply the appropriate inequality for the indicated value of \(c\). $$ g(x)=3 f(x)-3 \quad g^{\prime}(-5) \quad 0 $$

Prove that if \(p(x)=a_{n} x^{n}+\cdots+a_{1} x+a_{0}\) and \(q(x)=b_{m} x^{m}+\cdots+b_{1} x+b_{0}\left(a_{n} \neq 0, b_{m} \neq 0\right),\) then \(\lim _{x \rightarrow \infty} \frac{p(x)}{q(x)}=\left\\{\begin{array}{ll}0, & nm\end{array}\right.\)

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.