đề thi dap an hoc sinh gioi 11 2012-2013 THPT Diễn châu 2 nghe an

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(Thi gian 150 pht không k thi gian giao đ)
Câu 1(2 điểm),(-(./.0'12%3&45%')
67
cos 2 sin cos sinx x x x= −
87
5
2
16 sin 10 sin 5 sin 3
2
x x x− = −
,
Câu 2(1 điểm),9:(./..';<=!>>>#>?>@>A>B>C>D.E&'FGH0I1J.86K%'(LM<=&N%'(L%.E</M
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Câu 3(1 điểm),E'6('P0.'R6./.TM-.UM,P0&'R%'V&.'R6#TM-.UMIW>BTM-.UM&4X%3
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Câu 4(1 điểm),5O'b<=.c6
8
x
&4K%3Q'6(&4(F%.c6
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8
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Câu 5(1 điểm),5O<='d%3&e%3TM/&YZ&`%'&e%3!!<='d%3IUM&(L%.c6fg^<=
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n
u
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1 1
2013, 2 1, 1
n n
u u u n
+
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Câu 7(2,25 điểm),'K&Rf(b%m, GZOP&I(FO&4L%.d%'m,n7GZOj&0'k%3TM6
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87 'K*GZI(FO%rO&4K%3&6O3(/.m,/.I1s%3&'k%3TM6*<K%3<K%3Y:(m>
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, ,x AC y AD z= =
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Câu 8 (0,5 điểm),'K&6O3(/.m.E 
, ,a BC b AC c AB= = =
>
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Giám thị coi thi không giải thích gì thêm
Họ và tên thí sinh……………………,,,,,,,,, Giámthị 1:…………………………………
Số báo danh………………………x,,,,,,,,,, Giám thị 2:…………………xxxxx
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Câu Ni dung Đim

67&
( )
( )
2 2
cos sin si n cos sin 0x x x x x⇔ − − − =
( ) ( )
cos sin cos sin sin 1 0x x x x x
 
⇔ − + − =
 
( )
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x
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2
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2
2
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16 sin 16sin sin 16 sin 4 sin cos 2 2 cos 2 1
2
x
x x x x x x x
−
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4 sin 8sin cos 2 4 sin . sin 5 5sin 3 10sin
2
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x x x x x x x
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2
4
sin 5 0
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5 2
4

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nĐáp án gồm 3 trang. Học sinh giải theo cách khác đng vẫn cho đim tối đa7
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