Solve the separable differential equation

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hardatwork
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Homework Statement



dx/dy=-0.6y
y(0)=5

Homework Equations





The Attempt at a Solution


I tried solving it by
[tex]\int[/tex]dy/y=[tex]\int[/tex]-0.6dx
ln(y)=-0.6x+c
ln(y(0))=-0.6(0)+c
ln(5)=c
ln(y)=-0.6x+ln(5)
y=[tex]e^{-0.6x}[/tex]+5
But its incorrect. I don't know what I am doing wrong. Can someone helping see what I am doing wrong? Thank You so much!
 
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You should solve for your function before substituting initial conditions. Remember that [tex]e^{ln|y|}=y[/tex]
 
hardatwork said:

Homework Statement



dx/dy=-0.6y

Is this a typo? Do really mean dx/dy=-0.6y, or do you mean dy/dx=-0.6y?

[tex]\int[/tex]dy/y=[tex]\int[/tex]-0.6dx
ln(y)=-0.6x+c
ln(y(0))=-0.6(0)+c
ln(5)=c
ln(y)=-0.6x+ln(5)
y=[tex]e^{-0.6x}[/tex]+5
But its incorrect. I don't know what I am doing wrong. Can someone helping see what I am doing wrong? Thank You so much!

If [itex]\ln y=-0.6x+\ln 5[/itex], then

[tex]y=e^{-0.6x+\ln 5}=e^{\ln 5}e^{-0.6x}=5e^{-0.6x}\neq e^{-0.6x}+5[/tex]
 
Okay. That makes so much sense. Thank You so much