/*! 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 18 First verify that \(y(x)\) satis... [FREE SOLUTION] | 91Ó°ÊÓ

91Ó°ÊÓ

First verify that \(y(x)\) satisfies the given differential equation. Then determine a value of the constant \(C\) so that \(y(x)\) satisfies the given initial condition. Use a computer or graphing calculator ( if desired) to sketch several typical solutions of the given differential equation, and highlight the one that satisfies the given initial condition. $$ y^{\prime}=2 y ; y(x)=C e^{2 x}, y(0)=3 $$

Short Answer

Expert verified
The constant is \( C = 3 \), giving the solution \( y(x) = 3e^{2x} \).

Step by step solution

01

Differentiate the function

Let's first differentiate the given function \( y(x) = C e^{2x} \) with respect to \( x \). Using the chain rule, we find \[ \frac{dy}{dx} = C \cdot \frac{d}{dx}(e^{2x}) = C \cdot 2e^{2x} = 2Ce^{2x}. \] This gives us the derivative \( y'(x) = 2Ce^{2x} \).
02

Verify the differential equation

Let's check if \( y'(x) = 2Ce^{2x} \) satisfies the differential equation \( y' = 2y \). Substitute \( y(x) = Ce^{2x} \) into \( 2y \): \[ 2y = 2(Ce^{2x}) = 2Ce^{2x}. \] We see that \( y'(x) = 2Ce^{2x} \) matches \( 2y = 2Ce^{2x} \), verifying that \( y(x) \) satisfies the differential equation.
03

Determine the constant using the initial condition

Now, use the initial condition \( y(0) = 3 \). Substitute \( x = 0 \) and \( y(0) = Ce^{2\cdot 0} \) into the expression \( Ce^{2x} \): \[ y(0) = Ce^{0} = C = 3. \] Hence, the constant \( C \) must be \( 3 \).
04

Solution to the differential equation with initial condition

Having determined \( C = 3 \), the specific solution of the differential equation that satisfies the initial condition is \( y(x) = 3e^{2x} \).
05

Sketch graph of solutions

To sketch the solution, several curves representing \( y(x) = Ce^{2x} \) for different values of \( C \) can be plotted. Highlight the curve with \( C=3 \), namely \( y(x) = 3e^{2x} \), which passes through the point \((0, 3)\), showing it satisfies the initial condition.

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.

Initial Value Problem
An Initial Value Problem (IVP) in differential equations involves finding a solution to a differential equation that also satisfies a given initial condition. In this exercise, you're given the differential equation \( y' = 2y \) and are tasked with finding a function that fits this equation and passes through a specific point, given here as \( y(0) = 3 \). Usually, the problem will specify a particular value of the function at a given point (here, \( x=0 \)). By specifying an initial condition, it makes the solution unique. When solving an IVP, we derive the general solution of the differential equation first. Then, the initial condition helps to find the particular constant that satisfies this specific case. Here, by applying \( y(0) = 3 \), the constant \( C \) in the function \( y(x) = Ce^{2x} \) is determined to be 3, leading to the unique solution \( y(x) = 3e^{2x} \).
Solution Verification
Verifying a solution means ensuring that your proposed function satisfies the original differential equation. In this exercise, the function \( y(x) = Ce^{2x} \) needs to be verified to confirm it satisfies the differential equation \( y' = 2y \). We first differentiate \( y(x) \) to find \( y' \). The differentiation yields \( y'(x) = 2Ce^{2x} \). By substituting the function back into the differential equation, both sides of the equation \( y' = 2y \) should match.For \( y(x) = Ce^{2x} \), substituting gives \( 2y = 2Ce^{2x} \) which matches \( y'(x) \). Thus, the function is verified as a valid solution to the differential equation. Verification ensures mathematical accuracy and guarantees the solution will behave as expected in modeling scenarios.
Exponential Growth
Exponential growth occurs when a quantity increases at a rate proportional to its current value. This growth pattern appears frequently in natural phenomena like populations and bank interest, among other areas.In the context of this exercise, the equation \( y' = 2y \) suggests exponential growth since the rate of change of \( y \) is proportional to the function itself. The solution, \( y(x) = Ce^{2x} \), represents exponential growth where the base \( e \) is raised to the power of \( 2x \), leading to rapid increases as \( x \) grows. The constant \( C \) determines the initial value and adjusts the growth curve's steepness. Specifically, as \( C \) was determined to be 3 from the initial condition, \( y(x) = 3e^{2x} \) models a situation where the growth rate doubles with every unit increase in \( x \). Exponential growth can lead to very large values very quickly, highlighting its significance in real-world modeling where understanding growth behavior is crucial.
Graphing Solutions
Graphing solutions of a differential equation helps visualize the behavior of the function over a range of values. It provides insight into the dynamics of the system described by the equation.For this exercise, the general solution \( y(x) = Ce^{2x} \) can have graphs plotted for various values of \( C \). Each graph will show an exponential growth curve starting from a different initial point. The specific solution derived from the initial condition, \( y(x) = 3e^{2x} \), is highlighted to illustrate that it meets the specified starting condition \( y(0)=3 \). A graphing utility can be used for sketching these curves. Typically, you will see each curve starting at a point defined by \( C \) and moving upwards rapidly. Highlighting the curve that runs through \((0, 3)\) effectively showcases how the initial value impacts the entire trajectory of the solution, offering a vivid way to understand solution dynamics.

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

A certain moon rock was found to contain equal numbers of potassium and argon atoms. Assume that all the argon is the result of radioactive decay of potassium (its half-life is about \(1.28 \times 10^{9}\) years) and that one of every nine potassium atom disintegrations yields an argon atom. What is the age of the rock, measured from the time it contained only potassium?

Verify that the given differential equation is exact; then solve it. $$ \left(1+y e^{x y}\right) d x+\left(2 y+x e^{x y}\right) d y=0 $$

The barometric pressure \(p\) (in inches of mercury) at an altitude \(x\) miles above sea level satisfies the initial value problem \(d p / d x=(-0.2) p, p(0)=29.92\) (a) Calculate the barometric pressure at \(10,000 \mathrm{ft}\) and again at 30,000 ft. (b) Without prior conditioning, few people can survive when the pressure drops to less than 15 in. of mercury. How high is that?

Verify that the given differential equation is exact; then solve it. $$ (2 x+3 y) d x+(3 x+2 y) d y=0 $$

Problems deal with a shallow reservoir that has a one-square-kilometer water surface and an average water depth of 2 meters. Initially it is filled with fresh water, but at time \(t=0\) water contaminated with a liquid pollutant begins flowing into the reservoir at the rate of 200 thousand cubic meters per month. The well-mixed water in the reservoir flows out at the same rate. Your first task is to find the amount \(x(t)\) of pollutant (in millions of liters) in the reservoir after 1 months. The incoming water has a pollutant concentration of \(c(t)=10\) liters per cubic meter \(\left(\mathrm{L} / \mathrm{m}^{3}\right)\). Verify that the graph of \(x(t)\) resembles the steadily rising curve in Fig. 1.5.9, which approaches asymptotically the graph of the equilibrium solution \(x(t)=20\) that corresponds to the reservoir's long-term pollutant content. How long does it take the pollutant concentration in the reservoir to reach \(10 \mathrm{~L} / \mathrm{m}^{3} ?\)

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.