2008年苏州数学试题
解决方案:
(1)OH是Rt△OPC的斜边上的高度,ao = bo =√2;
= = & gt△AOB是等腰Rt△,
= = & gtOH是等腰Rt△AOB的斜边上的中线和垂直线。
= = & gtAH = HB = = OH = AO/√2 =√2/√2 = 1;
P(-2)直线y = kx+b与x轴相交于p (-2,0),
= = & gt0=-2k+b
= = & gtk = b/2;
在C. (0,oc)处与y轴相交
= = & gtOC=-0*k+b
= = & gtb = OC
a和b在直线上y = kx+b,
= = & gt在Rt△PHO中,OH=1,OP=2,
= = & gt& ltHPO=30,
= = & gt在Rt△PCO中,op = 2,
= = & gtOC/OP=1/√3,
= = & gtOC = OP * 1/√3 = 2 * 1/√3 = 2/√3,
= = & gtb=OC=2/√3
= = & gtk=b/2=(2/√3)/2=3/√3
所以:
1)OH的长度= 1;k=3/√3,b = 2/√3;
##