By using this site, you agree to our Privacy Policy and our Terms of Use. Close
Alright, I'm studying for a maths exam on monday and this question has me completely stumped.

Essentially its a seperation of variables question and it involves the equation

ds/dt=k(a-s)

Where 'a' is the initial value and the initial value is 50.

From what I have worked out this is

1/(50-s)ds = kdt

-ln(50-s) = kt
ln(50-s) = -kt
50-s = e^-kt
s = 50 - e^kt

However the correct answer is apparently s = 50(1 - e^kt) and I can't figure out how on earth they got that. Be very useful if somebody can help me out here.