|
再与方程组中两式分别相减,得
|
(2)由(1)可知,A(5,0),B(3,2),
如图1,当m>0时,
过B点作BD⊥x轴,垂足为D,
则S△ABQ=S梯形BDEQ-S△ABD-S△AQE
=
1 |
2 |
1 |
2 |
1 |
2 |
=m+1;
当m<0时,如图2所示,
过点B作BM⊥EQ于点M,
则S△ABQ=S△BMQ-S△AEQ-S梯形AEMB
=
1 |
2 |
1 |
2 |
1 |
2 |
=3-
3 |
2 |
1 |
2 |
=-m-1.
(3)∵S梯形OABC=
1 |
2 |
依题意,得|m|+1=
1 |
2 |
解得m=±3,
∴Q(6,3)或(6,-3).