I wonder if there is any difference between:
I have known about calculus.
I'm familiar with calculus.
To me, I assume those are equivalent, but I think there is something different between them that is hard to tell.
To illustrate this problem, I will give an example. Suppose, I had been learning calculus for 2 years when I went to college. Someone in the present time asks me about calculus but I tell them that I didn't finish studying (I hadn't finished the whole lesson, but currently I'm not studying calculus anymore).
In the example above when I want to tell I've ever learnt calculus, which one should I use between (have known) and (familiar with)? I hope you could elaborate your answer. Thanks!