急:求 南京市2008 2009学年度第一学期期末调研测试卷数学答案,南京市20...
1:[-1,2] 2:二3:44:20005:16:(x-3)^2 y^2=107:1/6π8:1/39:110:2&411:2√2/3π12:-1/213:1/214:[6,12]15。(1)由正弦定理得:sinC/c=sinB/b因3bsinC-5csinBcosA=0故3bc-5cbcosA=0故cosA=3/5因sinA>0故sinA=4/5(2)这样tanA=4/3因tan(A-B)=tanA-tanB/1 tanAtanB=((4/3)-tanB)/(1 (4/3)tanB)=-2/11故tanB=2由tanC=tan(π-A-B)=-tan(A B)=-(tanA tanB)...全部
1:[-1,2] 2:二3:44:20005:16:(x-3)^2 y^2=107:1/6π8:1/39:110:2&411:2√2/3π12:-1/213:1/214:[6,12]15。(1)由正弦定理得:sinC/c=sinB/b因3bsinC-5csinBcosA=0故3bc-5cbcosA=0故cosA=3/5因sinA>0故sinA=4/5(2)这样tanA=4/3因tan(A-B)=tanA-tanB/1 tanAtanB=((4/3)-tanB)/(1 (4/3)tanB)=-2/11故tanB=2由tanC=tan(π-A-B)=-tan(A B)=-(tanA tanB)/(1-tanAtanB)=-((4/3) 2)/(1-(4/3)*2)=216。
(1)连接A1B,BC1因直三棱柱中侧面BB1C1C为矩形故0为BC1中点又E为A1C1中点故OE为中位线 故OE//BA1又因BA1属于平面AA1B1B,OE不属于平面故OE//面AA1B1B剩下的还没写呢`。
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