1.求y=3^(x-1)-2 (x1)值域 2.求y=log1/2(x^2-4x+5)值域 3.y=0(x>=0);y=x (x
问题描述：
1.求y=3^(x-1)-2 (x1)值域 2.求y=log1/2(x^2-4x+5)值域 3.y=0(x>=0);y=x (x
答
1 x1 (1,+无穷)
2.x^2-4x+5=(x-2)^2+1>=1
值域为(-无穷,0]
3.y=0(x>=0)
值域 恒为0
y=x(x