# Thread: D.E question, is this correct

1. ## D.E question, is this correct

Hi everyone
Need help to verify my answers for this question.Thank you in advance for all kind help & support.

Determine the type of the following differential equations including the ordinary or partial differential equations,order,linearity & homogeneity.

a)$\displaystyle \frac{dy}{dx}-4y=0$
Linear, First order, Homogenous.

b) $\displaystyle \frac{dy}{dt}+\frac{dx}{dt}=0$
Partial differential equation.

c) $\displaystyle \frac{d^2y}{dt^2}-3\frac{dy}{dt}+7y=0$
Linear, 2nd order, homogenous.

d)$\displaystyle (\frac{dy}{dt})^2+3y=0$
Non-linear,First order, 2nd degree

e) $\displaystyle \frac{d^2x}{dt}+2\frac{dx}{dt}+7x=sint$
Linear,2nd order, Non-homogenous

Thank you in advance for all help & support.

2. Originally Posted by anderson
Hi everyone
Need help to verify my answers for this question.Thank you in advance for all kind help & support.

Determine the type of the following differential equations including the ordinary or partial differential equations,order,linearity & homogeneity.

a)$\displaystyle \frac{dy}{dx}-4y=0$
Linear, First order, Homogenous.

b) $\displaystyle \frac{dy}{dt}+\frac{dx}{dt}=0$
Partial differential equation.

c) $\displaystyle \frac{d^2y}{dt^2}-3\frac{dy}{dt}+7y=0$
Linear, 2nd order, homogenous.

d)$\displaystyle (\frac{dy}{dt})^2+3y=0$
Non-linear,First order, 2nd degree

e) $\displaystyle \frac{d^2x}{dt}+2\frac{dx}{dt}+7x=sint$
Linear,2nd order, Non-homogenous

Thank you in advance for all help & support.
Everything is good except (b). THe notation says that $\displaystyle x$ and $\displaystyle y$ are functions of $\displaystyle t$ so this would be an ordinary differential equation (but you would need another equation to complete the system).