Having trouble remembering my calculus. Need help with this equation.

[mmm309]

dy/dt+5*y;y(0)=1

 

[srmichael]

dy/dt+5*y;y(0)=1

You sure it's not \(\displaystyle \displaystyle \frac{dy}{dt}=5y\)??

 

[mmm309]

My Bad. Equation should read dy/dt+5*y=0; y(0)=1

 

[srmichael]

My Bad. Equation should read dy/dt+5*y=0; y(0)=1

Do you remember how to separate the variables and then integrate?

\(\displaystyle \displaystyle \frac{dy}{dt}+5y=0\)

\(\displaystyle \displaystyle \frac{dy}{dt}=-5y\)

\(\displaystyle \displaystyle \frac{dy}{y}=-5dt\)

Now integrate both sides and let us know if you get stuck.

 

[afrazer721]

dy/dt+5*y;y(0)=1

Originally Posted by mmm309
My Bad. Equation should read dy/dt+5*y=0; y(0)=1



Do you remember how to separate the variables and then integrate?

lny=-5t
e^lny=e^-5t
y=e^-5t
y(0)=e^-5(0)
y(0)=1.