Linear Differential Equation: Solving for M with Integrating Factor of .5

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SUMMARY

The discussion centers on solving the linear differential equation dM/dT = 0.5M - 24. The correct solution is M = 48 + ke^(-0.5t), where k is determined by the initial condition M(0) = 7, leading to k = 7 - 48 = -41. The user incorrectly applied the integrating factor and misinterpreted the initial condition, resulting in the erroneous expression M = 55 - 48e^(-0.5t). The equation is separable, and an integrating factor is unnecessary.

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Homework Statement



dM/dT = .5m-24

I know this is a linear differential equation, with an integrating factor of .5
I get my final answer to be M = 48+ke^(-.5t)

Next, when t = 0, M = 7e^(.5t)...

Giving me k = 7e^(.5t) - 48

so to solve for M..

M = 48 + (7e^(.5t)-48)e^(-.5t)

And finally I get 55-48e^(-.5t)=M which I guess isn't right. Anyone help out what I did wrong here?



My final answer that I get is 55-48e^(-.5t), which I guess is wrong. Where did I go wrong?
 
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The equation is separable. You don't really need an integrating factor. M=48+ke^(-.5t) is close, but you do you get the (-.5) factor in front of the t? That's wrong. And M=7*e^(.5t) at t=0 is kind of an odd way to state an initial condition. Do you mean M=7 at t=0?
 

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