I'm having a bit of trouble with some questions, I'm not sure whether it is from deficiancies in D.E or integration and would like some help if possible.
so here's an example.
A tank with 200L of pure water initially, has 4grams of salt per litre run into the tank at 1L per min. A well mixed solution is drained out at 3L per min.
I am to work out the amount of salt in the tank after t mins. Here's what im doing:
V=200-2t--------volume function of time
integrating factor= e^((integral of)3/200-2t)
Equation then becomes
This equation doesn't seem to be realistic as shouldn't the amount of salt in the container look like a parabola or trig(sin/cos) function?
Thanks in advance