(1)令x=0,则y=3,令y=0,则x=3,
故C(0,3)、B(3,0).
把两点坐标代入抛物线y=-x2+bx+c得,
,
c=3 ?9+3b+3=0
解得
,
c=3 b=2
故抛物线的解析式为:y=-x2+2x+3;
(2)设P点坐标为(x,-x+3),
∵C(0,3)
∴S△PAC=S△ABC-S△PAB=
S△PAB,1 2
即
|AB|×3-1 2
|AB|×(-x+3)=1 2
×1 2
|AB|×(-x+3),1 2
解得x=1,
故P(1,2).