①因为周长相等的两个圆,面积一定相等,所以周长相等的两个长方形,面积也一定相等。②圆锥的体积是等底等高的圆柱体的。③xy=k+5.4(k+5.4≠0),当k一定时,x和y成反比例。④一个圆的半径增加10%,它的面积增加21%。⑤甲数比乙数多,乙数比甲数少。
A.4个 | B.3个 | C.2个 | D.1个 |
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