Make use of vectors to re-write the following second order

geekotakuglh

geekotakuglh

Answered question

2022-02-17

Make use of vectors to re-write the following second order differential equation into a 1st order differential equation. (note: I do not need to solve it).
2.1x2d2ydx23e2xy4dydx=6y
where y=4.2 and dydx=3.1 when x=0.5.
Im not sure were to begin any help is greatly appreciated.

Answer & Explanation

zahrkao8vm

zahrkao8vm

Beginner2022-02-18Added 10 answers

The way to rewrite one second-order equation into two first-order ones is to establish a second function, and tie it in with what's already there. I am sure there are problems with incredibly clever functions to choose that just makes the problem immediately solvable, but the standard choice is z=dydx. That is one equation, and it allows you to rewrite the original equation to get rid of all those second derivatives:
2.1x2d2ydx23e2xy4dydx=6y
2.1x2dzdx3e2xy4z=6y
which gives the two differential equations
{dzdx=32.1x2e2xy462.1x2ydydx=z
also known as the first order vector differential equation
ddx(z,y)=(32.1x2e2xy462.1x2y,z)
with initial value (3.1,4.2) for x=0.5.

Do you have a similar question?

Recalculate according to your conditions!

New Questions in Differential Equations

Ask your question.
Get an expert answer.

Let our experts help you. Answer in as fast as 15 minutes.

Didn't find what you were looking for?