【附5套中考模拟试卷】河北省衡水?019-2020学年中考数学一模试卷含解析 - 百度文库

ͣ 9C

ѡֱݵij˷ͻij˷ͬݵij˷ʵ㣬Ȼѡȷѡ ⡿

⣺A. a3?a2=a5ԭʽ󣬹ʱѡ B. (a2)3=a6ԭʽ󣬹ʱѡ C.

9=3ԭʽȷʱѡȷ

D. 25ͬܺϲʱѡ ѡC. 㾦

⿼ݵij˷ij˷ ʵ㣬 ͬݵij˷Ĺؼݵ㷨. 10C

ıABCDΣ AD=BCDAB=ABC=90㣬 BP=CQ AP=BQ

?AD?AB?ڡDAPABQУ??DAP??ABQ

?AP?BQ?DAPաABQ P=Q ߡQ+QAB=90㣬 P+QAB=90㣬 AOP=90㣬 AQDP ʢȷ

ߡDOA=AOP=90㣬ADO+P=ADO+DAO=90㣬 DAO=P DAOסAPO

AOOP? ODOAAO2=OD?OP AEAB AEAD ODOE

OA2OE?OPʢڴ

??FCQ??EBP? ڡCQFBPE??Q??P?CQ?BP?CQFաBPE CF=BE DF=CE

?AD?CD?ڡADFDCEУ??ADC??DCE

?DF?CE?ADFաDCE

SADFSDFO=SDCESDOF SAOD=SıOECFʢȷ BP=1AB=3 AP=4

ߡAOPסDAP

PBPA4?? EBDA3BE=

313QE=

44ߡQOEסPAD

13QOOEQE

???4PAADPD53913QO=OE=

20512AO=5QO=

5OE13tanOAE==ʢȷ

OA16ѡC

㾦⿼εжʣȫεжʣεʣǺĶ壬

ȫεжǽĹؼ 11B

ƽƵĻʣóıABFDܳ=AD+AB+BF+DF=1+AB+BC+1+ACɵó𰸣 ⣬ܳΪ8λġABCرBCƽ1λõDEF AD=1BF=BC+CF=BC+1DF=AC ֡AB+BC+AC=8

ıABFDܳ=AD+AB+BF+DF=1+AB+BC+1+AC=1 ѡC

㾦⿼ƽƵĻʣƽƲıͼε״ʹСھƽƣӦ߶ƽȣӦ߶ƽȣӦȣõCF=ADDF=ACǽĹؼ 12B

߿ڷa0ߵĶԳλÿɵb0yĽλÿɵc0ɶԢٽжϣxĽõb24ac0a0ɶԢڽжϣOA=OCɵõAc0ٰAc0y=ax2+bx+cac2bc+c=0߳cɶԢ۽жϣAx10Bx20OA=x1OB=x2xĽõx1x2Ƿax2+bx+c=0a0øϵĹϵõx1?x2=OA?OB=ɶԢܽжϣ ⣺߿£ a0

ߵĶԳyҲ࣬ b0

yĽxϷ c0

abc0Ԣȷ x2㣬 =b24ac0 a0

0Ԣڴ

C0cOA=OC Ac0

Ac0y=ax2+bx+cac2bc+c=0 acb+1=0Ԣȷ Ax10Bx20

߶κy=ax2+bx+ca0ͼxύAB㣬 x1x2Ƿax2+bx+c=0a0 x1?x2=

OA?OB=Ԣȷ ѡB

㣺κͼϵĹϵ

⣺⹲6С⣬ÿС4֣24֣ 131

ԭʽ2(2x+y)+1Ȼ˼ó𰸣 2+1=1 ⣺ԭʽ=2(2x+y)+1=2

㾦Ҫ˼⣬ڻͣҵǽĹؼ 143x1

ݵںΪΪɵó. ⡿

ߵP2x-6x-5ڵޣ

-3x1ʴΪ-3x1. 㾦

⿼˵ꡢһԪһβʽ飬Ĺؼ֪ƽֱϵе޺ᡢķ. 15m4.

бʽõV424m0Ȼⲻʽ.

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