[不等式][謝謝]

[LATEX]

擷取ddddd.GIF (3.26 KiB) 已瀏覽 19234 次

[thepiano]

-1 ≦ a ≦ 1
0 ≦ a + 1 ≦ 2

-1 ≦ a + b ≦ 1
-1 - a ≦ b ≦ 1 - a
-a ≦ b + 1 ≦ 2 - a

-a(a + 1) ≦ (a + 1)(b + 1) ≦ (2 - a)(a + 1)
-2 ≦ -a^2 - a ≦ (a + 1)(b + 1) ≦ -a^2 + a + 2 ≦ 9/4