y=根号下-x(x=0) B.y=-x^2(x>=0) C.y=x^2(x

问题描述:

y=根号下-x(x=0) B.y=-x^2(x>=0) C.y=x^2(x

B
y^2=-x
x=-y^2
y=-x^2
因为原函数定义域为x=0
所以现在的定义域为x>=0