In Problems 3–8, determine whether the given function is a solution to the given differential equation.

θ=2e3t-e2t,d2θdt2-θdt+3θ=-2e2t

Short Answer

Expert verified

The given function is not a solution to the given differential equation.

Step by step solution

01

Differentiating the given equation w.r.t. (with respect to) t

Firstly, we will differentiate θ=2e3t-e2twith respect to t,

dt=6e3t-2e2t

Again, differentiatingwith respect to t,

d2θdt2=18e3t-4e2t

02

Simplification

Putting the values from step 1 in the L.H.S. (Left-hand side) of the given differential equation,

d2θdt2-θdθdt+3θ=18e3t-4e2t-2e3t-e2t×6e3t-2e2t+3×2e3t-e2td2θdt2-θdθdt+3θ=18e3t-4e2t-12e6t-4e5t-6e5t+2e4t+6e3t-3e2td2θdt2-θdt+3θ=24e3t-7e2t-12e6t-4e5t-6e5t+2e4t

which is not the same as the R.H.S. (Right-hand side) of the given differential equation.

Hence,θ=2e3t-e2t is not a solution to the differential equationd2θdt2-θdt+3θ=-2e2t.

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 Vaia!

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

Find a general solution for the differential equation with x as the independent variable:

y'''+3y''4y'6y=0

Variation of Parameters. Here is another procedure for solving linear equations that is particularly useful for higher-order linear equations. This method is called variation of parameters. It is based on the idea that just by knowing the form of the solution, we can substitute into the given equation and solve for any unknowns. Here we illustrate the method for first-order equations (see Sections 4.6 and 6.4 for the generalization to higher-order equations).

(a) Show that the general solution to (20)dydx+P(x)y=Q(x) has the formy(x)=Cyh(x)+yp(x),whereyh ( 0is a solution to equation (20) when Q(x)=0,

C is a constant, andyp(x)=v(x)yh(x) for a suitable function v(x). [Hint: Show that we can takeyh=μ-1(x) and then use equation (8).] We can in fact determine the unknown function yhby solving a separable equation. Then direct substitution of vyh in the original equation will give a simple equation that can be solved for v.

Use this procedure to find the general solution to (21) localid="1663920708127" dydx+3xy=x2, x > 0 by completing the following steps:

(b) Find a nontrivial solutionyh to the separable equation (22) localid="1663920724944" dydx+3xy=0, localid="1663920736626" x>0.

(c) Assuming (21) has a solution of the formlocalid="1663920777078" yp(x)=v(x)yh(x) , substitute this into equation (21), and simplify to obtain localid="1663920789271" v'(x)=x2yh(x).

d) Now integrate to getlocalid="1663920800433" vx

(e) Verify thatlocalid="1663920811828" y(x)=Cyh(x)+v(x)yh(x) is a general solution to (21).

Using the Runge–Kutta algorithm for systems with h = 0.05, approximate the solution to the initial value problem y'''+y''+y2=t;y(0)=1,y'(0)=0,y''(0)=1 at t=1.

Question: In Problems 3–8, determine whether the given function is a solution to the given differential equation.

y=3sin2x+e-x, y''+4y=5e-x

In problems 1-6, identify the independent variable, dependent variable, and determine whether the equation is linear or nonlinear.

y3d2xdy2+3x-8y-1=0

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.

Sign-up for free