In my studies, I encountered a question which I did not know how to do. The answer referred to implicit differentiation but I did not understand the steps undertaken, so could someone explain to me how to do the following question?

The answer states that . Where does the come from?, show that .

Then I had problem with Euler's method with the question:

How do I use Euler's method if all I have if ?Given that when , use Euler's method with a step-size of to estimate the value of when