Harry was walking along the street when he found a bottle. He opened it and out came a genie (精灵).
“Make
“Well,” Harry said, “I
“I’ll give you a one-time good luck charm (咒语). To start it, say ‘123’. When you’re done, say ‘1234’,” the genie said.
Harry couldn’t believe his good luck. That night, he knocked on the rich man’s office.
“Come
Harry went inside. Before he started, he quietly said “123” to himself. He thought everything would go well.
He opened up his mouth

同类型试题

y = sin x, x∈R, y∈[–1,1],周期为2π,函数图像以 x = (π/2) + kπ 为对称轴
y = arcsin x, x∈[–1,1], y∈[–π/2,π/2]
sin x = 0 ←→ arcsin x = 0
sin x = 1/2 ←→ arcsin x = π/6
sin x = √2/2 ←→ arcsin x = π/4
sin x = 1 ←→ arcsin x = π/2


y = sin x, x∈R, y∈[–1,1],周期为2π,函数图像以 x = (π/2) + kπ 为对称轴
y = arcsin x, x∈[–1,1], y∈[–π/2,π/2]
sin x = 0 ←→ arcsin x = 0
sin x = 1/2 ←→ arcsin x = π/6
sin x = √2/2 ←→ arcsin x = π/4
sin x = 1 ←→ arcsin x = π/2

