根据图象,函数应为：y=-2/3x+2
A：y=0
-2/3x+2=0
x=3
A(3,0)
B：x=0
y=-2/3*0+2=2
B(0,2)
|AB|=√(3²+2²)=√13
|BC|=|AB|=√13
SΔABC=1/2|AB|*|BC|
=1/2*√13*√13
=13/2
P(1,a)到AB的距离：
d=|2/3*1+a-2|/√((2/3)²+1²)
=|a-4/3|/(√13/3)
=3|a-4/3|/√13
SΔABP=1/2|AB|*d
=1/2*√13*3|a-4/3|/√13
=3/2|a-4/3|
SΔABC=SΔABP
13/2=3/2|a-4/3|
a-4/3=±13/3
a=(4±13)/3
a1=(4+13)/3=17/3
a2=(4-13)/3=-3