領域

円領域を描きましょう。

領域の入れ替え

正解

a = Element({1, 2, 4, 5, 8, 9, 10, 13, 16}, Random[1, 9])
e(x, y) = x^(2) + y^(2)  <  5
A = PointIn(e)
f(x, y) = (x - x(A))^(2) + (y - y(A))^(2) > 0.1
s = -1
B = PointIn(f)
n: (Random[0, 1] * 2) - 1
f0 = Expand(x^(2) + y^(2) - a)
text3 = If(n ≟ 1, "\le ", "\ge ")
text1: "" + (LaTeX[f0]) + "" + (LaTeX[text3]) + "0を表すように赤い点を動かしましょう．"
d(x, y) = (s * ((x(A) - x)^(2) + (y(A) - y)^(2) - (x(A) - x(B))^(2) - (y(A) - y(B))^(2))) ≥ 0
ans1: x(A) ≟ 0 ∧ y(A) ≟ 0
ans2: (x(B) * x(B)) + (y(B) * y(B)) ≟ a
ans3: n ≟ (-s)