2018年中考数学真题分类汇?第二?专题22 等腰三角形试?含解? - 百度文库 ر

ʣĹؼ֤A=C

8.2018??11֣ͼ֪κy=ax+bx+cͼxཻA10B30㣬yཻڵC03 1κıʽ

2Pǵκͼһ㣬PHxڵHBCڵMPC

߶PMֵ

ڵPCMPMΪһĵʱP꣮

2

1ݴϵɵô𰸣

2ٸƽyֱľǽϴС꣬ɵöκݶκʣɵô𰸣

ڸݵεĶ壬ɵ÷̣ݽ̣ⷽɵô𰸣 𡿽⣺1ABC뺯ʽ

ã

2

κıʽy=x2x3 2BCĽΪy=kx+b BC뺯ʽ

BCĽΪy=x3

Mnn3Pnn2n3

2

25

PM=n3n2n3=n+3n=n+ n=ʱPM=

ڵPM=PCʱn+3n=n+n2n3+3 n1=0⣬ᣩn2=n2n3=22P

2

2

2

2

2

2

2

222

⣬ᣩn3=

3=21

2

2

2

1

PM=MCʱn+3n=n+n3+3

n1=0⣬ᣩn2=7⣬ᣩn3=1 n2n3=123=4 P14

P14

2

1

2

2

⿼˶κۺ⣬⣨1Ĺؼôϵʽ⣨2ٵĹؼƽyֱľǽϴСóκ˶κʣ⣨2ڵĹؼõεĶónķ̣ҪۣԷ©

26