Science talk:Math Exam Resources/Courses/MATH102/December 2015/Question 07

Hi Ziming,

Unfortunately, the solution to the question is not (a) because if t = 0, then F(t) = -800. The answer is (c) as F(0) = 800 and

dF/dt = 100 - r(100/r + (800 - 100/r)e^{-rt}) = 100 - rF(t)

Brian

Fixed. Thanks Brian :)

Hi Brian and Ziming,

I made some changes to the solution to make it easier to read. Furthermore, I kind of think it's good to have a solution in which the differential equation is explicitly solved instead of just using process of elimination, so I added a second solution. I've changed the tag from QBS to RS.