①B( -2,-2√3) ②设解析式为y=ax^2+bx,将( -2,-2√3)和(4,0)代入得:(方程徂省略),解得:a= -(√3)/6 ,b= (2√3)/3 ,∴y= -(√3)/6x^2+ (2√3)/3x③P(2,-2√3)
真没心思看