绵阳市高2014级第二次诊断性考试理科答案

绵阳市高 2014级第二次诊断性考试数学(理工类)参考解答及评分标准12560BACABCCDADCB452013-1114215355163567017cnan1ancn1 cn=(an2 an1)-(an1 an)=an2 2an1c1 a2 a1 2{an+1-an} 2 1()cnn1an+1-an=n+1an(anan1)(anan1)(a2a)a11n(n1)(n2)21n(n1)2121)2(11)ann(nnn1

an 1 4 8Sn=2(1-1)+2(1-1)+2(1-1)++2(11)22334nn1=2(11n)1=2n12n118()c2asinC=2sinA2C=2Asin2A=2sinA2sinAcosA=2sinA4ABCsinA≠0cosA=22A=64()an，bn1，cn2nN*C=2AsinC=sin2A=2sinAcosA数学（理工类）答案第 1页（共6页）cosAsinCc82sinA2ab2c2a2cabc2bc2a(n1)2(n2)2n2n2102(n1)(n2)2nn=4a=4b=5c=6ABC15ABC151219()x1701741761811791765626466706866y5?(170176)(6266)(174176)(6466)(181176)(7066)(179176)(6866)b(170176)2(174176)2(181176)2(179176)227≈0.7337??aybx660.73176=-62.48???ybxa0.73x62.48()x=185?0.7318562.48=72.57yM72.5720()Ccc=6a2-b2=6c2y21y2=b2(1-c2)=b2×a2c2=b4y=a2b2a2a2a22b22a2=2b4a2b4-b2-6=0b2=2b2=-3a2=82

1012b2aCx2y21482()PQxty1P(x1，y1)，Q(x2，y2)x2y2，821x(24)y22ty70txty，1y1+y2=2ty1y2=77t24t24数学（理工类）答案第 2页（共6页）xx2t(y1y)2812t24PQD(4，t)8t24t24N(1，y0)NPNQkNDkPQ1y0tt24t3t3ty0tN(1，t4t24)1t24t24NPQND3PQND23PQ224(441)2(t4t4)23(1t2)[(t22t)24t27]t2t2444(41)224t284(t28)224t284t24(t24)2t24(t24)2t210t1011lx10y101221()f(x)m1x2m1x22x2x2m≤0f(x)>0f(x)(0，)2m>0f(x)0x2mf(x)00x2mf(x)(0，2m)(2m，)f(x)min=f(2m)=m114ln2m2m2f(x)(0，)m1ln2m1<00me2m22m(0，e)52()t1f(1)m12ln11mt2lnt1xxxxmt2lnt1=0t1t2mlnt2t1t2t1=1t2=12tx1x2数学（理工类）答案第 3页（共6页）h(t)lnt2lnt12th(t)22th(t)010t10th(t)eet(0，1)h(t)t(1，)h(t)ee1 t1> >t2>0e112t1t22t12t21x1x2eeeeh(t1)h(2t2)e(x)h(x)h(2x)e(x)0x(0，1)eln(2x)12lnx1e(x)h(x)x)h(2x22e2(x)2ex(0，1)elnx10，x2(2x)2elnx1ln(2x)1lnx(x2)2(x)e=e2(22(22(2x)2x)2x)2eee2x(2x)1x)<[e]2x(2e2e(x)>0(x)(0，1)e(x)<(1)=0e

8数学（理工类）答案第 4页（共6页）x2y21522()3lx3y230Q(3cos，sin)M(3cos，11sin)22333236)33cossinsin(2224d22634623()t=2f(x)x1x2x≤1f(x)32xf(x)2x<1x<1221<x<2f(x)1f(x)2x≥2f(x)2x3f(x)2x>5x>522f(x)2{x|x<1x>5}22f(x)≥axa≤f(x)-xg(x)=f(x)-x-1≤x≤1g(x)=1+t-3xg(x)min=g(1)=t-21<x<tg(x)=t-1-xg(x)>g(1)=t-2t≤