For each of the following sets, sketch E, , and E. a) E = {(x, y) :

For each of the following sets, sketch E°, , and ϑE.
a) E = {(x, y) : x2 + 4y2 < 1}
b) E = {(x, y) : x2 - 2x + y2 = 0} U {(x, 0) : x ∈ [2, 3]}
c) E = {(x, y) : y > x2, 0 < y < 1}
d) E = {(x, y) : x2 - y2 < 1, -1 < y < 1}