/*! 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 30 Integrals with general bases Eva... [FREE SOLUTION] | 91Ó°ÊÓ

91Ó°ÊÓ

Integrals with general bases Evaluate the following integrals. \(\int_{1 / 3}^{1 / 2} \frac{10^{1 / p}}{p^{2}} d p\)

Short Answer

Expert verified
Question: Evaluate the integral \(\int_{1 / 3}^{1 / 2} \frac{10^{1 / p}}{p^{2}} d p\). Answer: \(\int_{1 / 3}^{1 / 2} \frac{10^{1 / p}}{p^{2}} d p = \ln{10} \cdot (10^3 - 10^2)\)

Step by step solution

01

Identify the substitution formula

To make the integration easier, we will perform a u-substitution. We will define a new variable \(u\) as follows: \(u = \frac{1}{p}\)
02

Find the derivative of u with respect to p

Find \(\frac{du}{dp}\). \(\frac{du}{dp} = -\frac{1}{p^2}\)
03

Solve for dp in terms of du

Rearrange the equation to get \(dp\) in terms of \(du\). \(dp = -p^2 du\)
04

Change the integral limits

As we are changing the variable from \(p\) to \(u\), we should also change the limits of integration. Use the substitution \(u = \frac{1}{p}\): For the lower limit (\(p = \frac{1}{3}\)), we have: \(u =\frac{1}{1/3} \Rightarrow u = 3\) For the upper limit (\(p = \frac{1}{2}\)), we have: \(u =\frac{1}{1/2} \Rightarrow u = 2\)
05

Replace p and dp in the integral

Rewrite the integral in terms of \(u\) and the new limits, using the substitution formulas from Steps 1 and 3. \(\int_{1 / 3}^{1 / 2} \frac{10^{1 / p}}{p^{2}} d p = -\int_{3}^{2} 10^u du\) Notice that the integral has flipped, as the order of the limits changed.
06

Integrate

Now, integrate the expression. \(-\int_{3}^{2} 10^u du = -(10^u \ln{10})\Big|_{3}^{2}\)
07

Evaluate the integral with the new limits

Finally, evaluate the integral using the new limits of integration: \(-(10^u \ln{10})\Big|_{3}^{2}= - \left[ (10^2 \ln{10}) - (10^3 \ln{10}) \right]\)
08

Simplify the result

Simplify the final expression. \(-(10^2 \ln{10}-10^3 \ln{10})=-\left[ \ln{10}\right] \cdot (10^2 - 10^3) = \ln{10} \cdot (10^3 - 10^2)\) The evaluated integral is: \(\int_{1 / 3}^{1 / 2} \frac{10^{1 / p}}{p^{2}} d p = \ln{10} \cdot (10^3 - 10^2)\)

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.

U-Substitution Technique
The u-substitution technique is a powerful method to simplify seemingly complex integrals. The main goal here is to transform the original integral into a new integral in terms of a variable 'u' that is often easier to integrate.

Imagine a scenario where you're on a road trip, and the path becomes too twisty to navigate smoothly. U-substitution is like finding a detour that's easier to drive, making your journey more manageable. In the exercise given, the function inside the integral, \(10^{1/p}\), is tricky to integrate with respect to 'p'. To ease the situation, we perform u-substitution and redefine 'p' as \(u = 1/p\), transforming the integral into a simpler form.

It's crucial to remember to find the derivative of 'u' with respect to 'p' and solve for 'dp' to express everything in terms of 'du'. This change of variable makes the integration process smoother, much like taking a straighter road to avoid the twists and turns.
Indefinite Integral
An indefinite integral represents a family of functions that all differ by a constant. This concept is akin to the various flavors of ice cream; they all come from the base of cream and sugar but have different mix-ins.

When you face an integral without specific limits, like blind baking a pie crust without the filling, what you are actually working with is an indefinite integral. It's unspecific until we add boundary conditions (limits) or additional information (the filling).

In calculus, indefinite integrals, denoted by the integral sign \(\int\) followed by a function, do not include upper or lower limits. Upon integrating, there's always a '+ C' tacked onto the end. This '+ C' is equivalent to saying 'plus any constant', because derivatives of constant numbers vanish, making them indistinguishable in the integration process.
Integration Limits
Think of integration limits like the starting and ending points of a hike. They define exactly where you begin and where you end. In the realm of calculus, these limits are used to calculate the area under a curve or the accumulation of quantities over a specific interval.

When you perform a u-substitution, the limits of integration must be adjusted to correspond with the new variable. In our example, when changing from 'p' to 'u', we recalibrate the trail markers; the lower limit changes from \(p = 1/3\) to \(u = 3\), and the upper limit from \(p = 1/2\) to \(u = 2\).

It's vital to swap these limits because they ensure that we are integrating over the correct region in our new, smoother 'u' space. Failing to change these limits would be as misplaced as using a map of Rome to navigate Paris!
Exponential Functions
Exponential functions, represented generally as \(a^x\), where 'a' is a positive constant, are the mathematical equivalents of compound interest in finance—they grow (or decay) at rates proportional to their current value. Such functions often appear in real-world scenarios like population growth, radioactive decay, and continuously compounding interest.

In our exercise, we're dealing with an exponential function, \(10^{1/p}\), which is a bit like having money in a bank account that changes its interest rate frequently. We use the u-substitution technique here to convert this unstable financial situation into a more manageable account with a steady, easily calculated interest (that is, an easier function to integrate).

When integrated, an exponential function results in a similar function multiplied by a factor, usually involving the natural logarithm of the base, as seen with the \(\ln{10}\) in the solution. This factor is crucial—it's like the rate that determines how fast your money grows in the bank.

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

Use a left Riemann sum with at least \(n=2\) sub-intervals of equal length to approximate \(\ln 2=\int_{1}^{2} \frac{d t}{t}\) and show that \(\ln 2<1 .\) Use a right Riemann sum with \(n=7\) sub-intervals of equal length to approximate \(\ln 3=\int_{1}^{3} \frac{d t}{t}\) and show that \(\ln 3>1\).

\(A\) 2000-liter cistern is empty when water begins flowing into it (at \(t=0\) ) at a rate (in \(\mathrm{L} / \mathrm{min}\) ) given by \(Q^{\prime}(t)=3 \sqrt{t},\) where \(t\) is measured in minutes. a. How much water flows into the cistern in 1 hour? b. Find and graph the function that gives the amount of water in the tank at any time \(t \geq 0\) c. When will the tank be full?

Power and energy Power and energy are often used interchangeably, but they are quite different. Energy is what makes matter move or heat up and is measured in units of joules (J) or Calories (Cal), where 1 Cal = 4184 J. One hour of walking consumes roughly \(10^{6} \mathrm{J},\) or \(250 \mathrm{Cal} .\) On the other hand, power is the rate at which energy is used and is measured in watts \((\mathrm{W} ; 1 \mathrm{W}=1 \mathrm{J} / \mathrm{s})\) Other useful units of power are kilowatts ( \(1 \mathrm{kW}=10^{3} \mathrm{W}\) ) and megawatts ( \(1 \mathrm{MW}=10^{6} \mathrm{W}\) ). If energy is used at a rate of \(1 \mathrm{kW}\) for 1 hr, the total amount of energy used is 1 kilowatt-hour \((\mathrm{kWh})=\) which is \(3.6 \times 10^{6} \mathrm{J}\) Suppose the power function of a large city over a \(24-\mathrm{hr}\) period is given by $$P(t)=E^{\prime}(t)=300-200 \sin \frac{\pi t}{12}$$ where \(P\) is measured in megawatts and \(t=0\) corresponds to 6:00 P.M. (see figure). a. How much energy is consumed by this city in a typical \(24-\mathrm{hr}\) period? Express the answer in megawatt-hours and in joules. b. Burning 1 kg of coal produces about 450 kWh of energy. How many kg of coal are required to meet the energy needs of the city for 1 day? For 1 year? c. Fission of 1 g of uranium- 235 (U-235) produces about \(16,000 \mathrm{kWh}\) of energy. How many grams of uranium are needed to meet the energy needs of the city for 1 day? For 1 year? d. A typical wind turbine can generate electrical power at a rate of about \(200 \mathrm{kW}\). Approximately how many wind turbines are needed to meet the average energy needs of the city?

At Earth's surface, the acceleration due to gravity is approximately \(g=9.8 \mathrm{m} / \mathrm{s}^{2}\) (with local variations). However, the acceleration decreases with distance from the surface according to Newton's law of gravitation. At a distance of \(y\) meters from Earth's surface, the acceleration is given by where \(R=6.4 \times 10^{6} \mathrm{m}\) is the radius of Earth. a. Suppose a projectile is launched upward with an initial velocity of \(v_{0} \mathrm{m} / \mathrm{s} .\) Let \(v(t)\) be its velocity and \(y(t)\) its height (in meters) above the surface \(t\) seconds after the launch. Neglecting forces such as air resistance, explain why \(\frac{d v}{d t}=a(y)\) and \(\frac{d y}{d t}=v(t)\) b. Use the Chain Rule to show that \(\frac{d v}{d t}=\frac{1}{2} \frac{d}{d y}\left(v^{2}\right)\) c. Show that the equation of motion for the projectile is \(\frac{1}{2} \frac{d}{d y}\left(v^{2}\right)=a(y),\) where \(a(y)\) is given previously. d. Integrate both sides of the equation in part (c) with respect to \(y\) using the fact that when \(y=0, v=v_{0} .\) Show that $$ \frac{1}{2}\left(v^{2}-v_{0}^{2}\right)=g R\left(\frac{1}{1+y / R}-1\right) $$ e. When the projectile reaches its maximum height, \(v=0\) Use this fact to determine that the maximum height is \(y_{\max }=\frac{R v_{0}^{2}}{2 g R-v_{0}^{2}}\) f. Graph \(y_{\max }\) as a function of \(v_{0} .\) What is the maximum height when \(v_{0}=500 \mathrm{m} / \mathrm{s}, 1500 \mathrm{m} / \mathrm{s},\) and \(5 \mathrm{km} / \mathrm{s} ?\) g. Show that the value of \(v_{0}\) needed to put the projectile into orbit (called the escape velocity) is \(\sqrt{2 g R}\)

Find the \(x\) -coordinate of the point(s) of inflection of \(f(x)=\operatorname{sech} x .\) Report exact answers in terms of logarithms (use Theorem 6.10 ).

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.