These questions are not designed to be clear, so it is natural to want to ask questions about them and discuss them. Please read and engage with them as best you can and ask questions and join in the discussion here. Part of your learning is to figure out what is being ask here, what these things mean, and what is expected. I view posting here as a sign of engagement and I appreciate that.
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Added Note:
How functions work: Consider the function f(x) = x^2. What is the nature of the related function f(x-9a)?
At x= 9a, what is f(x-9a)? zero right? And at x=10a one would get a^2, I think. True?
It is no different with our function, v(x) above. Whenever the argument is zero, the rules of the function yield v=-10 eV;
whenever the argument is greater than L/2 then the function is zero. For the function v(x-2a) the argument is zero when x=2a. For the function v(x+2a) the argument is zero when x=-2a. Although it could be something in the way I worded the problem or defined the function, I think in this case the issue is that you have not been taught clearly what a function is. If in resolving this you acquire a clearer concept of that, that would be the best outcome. The argument of the function is the key thing.
