What is the meaning of this analysis problem and give some hint please?
This problem was founded on Analysis 1 by Herbert Amann and Joachim Escher on page 100.
Determine the following subsets of $\Bbb R^2$ by drawing:
$$A = \{(x,y) \in \Bbb R^2 : |x-1| + |y+1| \leq 1\},$$
$$B = \{(x,y) \in \Bbb R^2 : 2x^2+y^2>1, |x| \leq |y|\},$$
$$C = \{(x,y) \in \Bbb R^2 : x^2-y^2>1, x-2y<1, y-2x<1\}.$$