設(shè)P(x,0),
則
0?3 |
x?(?2) |
0?7 |
x?5 |
解得x=
1 |
10 |
即P(
1 |
10 |
法二:由題意,知x軸是鏡面,
入射點(diǎn)A(-2,3)關(guān)于x軸的對(duì)稱(chēng)點(diǎn)為A1(-2,-3),
則點(diǎn)A1應(yīng)在反射光線所在的直線上,
即A1,P,B三點(diǎn)共線,
即kA1P=kPB,
0+3 |
x+2 |
7 |
5?x |
解得x=
1 |
10 |
即P(
1 |
10 |
0?3 |
x?(?2) |
0?7 |
x?5 |
1 |
10 |
1 |
10 |
0+3 |
x+2 |
7 |
5?x |
1 |
10 |
1 |
10 |