①把O(0,0)代入y=ax²+bx+c,得
c=0
把P(√3,3),E(5√3/2,0)代入y=ax²+bx+,得
3a+√3b=3
(75/4)a+(5√3/2)b=0
解之得 a=-2/3 b=5√3/3
∴y=(-2/3)x²+(5√3/3)x
②存在,设P(m,(-2/3)x²+(5√3/3)x)
⑴当△OPC∽△PQB时
PB/OC=BQ/CP
m-√3/3=3+(2/3)m²-(5√3/3)m/√3
m1=2√3,m2=√3(舍)
⑵当△OPC∽△QPB时
PB/PC=BQ/OC
m-√3/√3=3+(2/3)m²-(5√3/3)m/3
m1=3√3,m2=√3(舍)
综上,Q1(2√3,2),Q2(3√3,-3)