**1. How do I find the values of all of the constants in a problem involving differential equations ?**

There is usually enough information provided to find these values.

e.g When the problem says "initially" it means that t = 0.

**2. Will the differential equation always be given in an examination question?**

No, sometimes you will be told enough information to write down the differential equation yourself. It will usually be of the form y ' = ky