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⣺ 1712֣
֪Ȳ?an?͵ȱ?bn?Уa1?b1?1a2?b2a4?2?b3 1?an??bn?ͨʽ
*2am?bn(n?N)дm,nĹϵʽm?f(n)f(1)?f(2)?
1812֣
֪a?(sinx,?),b?(cosx,cos(2x? ?f(n)
12?6))f(x)?a?b.
1f(x)ĵ䣻
??2?2f(x)yҲֵС?an???ǰ
?anan?1?nTn.
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1912֣
?ABCУsinA?sinBsinC.
21?A?.
У?BĴС2bc?1,?ABCֵ. 320(С12)
ƽֱϵУOΪԭ㣬A,B,COC?120A?OB 33AC1֤A,B,C㹲ߣ 2ֵ
CB3֪A(1,cosx),B(1?cosx,cosx),x??0,СֵΪ?
2112֣
2???f(x)?OA?OC?(2m?)AB?23??3ʵmֵ 2 ֪g?x???2?a?lnx,h?x??lnx?ax2?a?R?,f?x??g?x??h'?x?,
h'?x?Ǻh?x?ĵ.
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1a?0ʱ,f?x?ļֵ;2?8?a??2ʱ,x1,x2?1,3,ʹ
??2f?x1??f?x2???m?ln3?a?2ln3?ln??a? ,mȡֵΧ.
3
뿼ڵ2223ѡһĵһǷ.ʱ2BǦڴϰѡĿͿ.
22.С10֣ѡ44: ϵ̣
ֱϵxOyУԲCIJΪ??x?3?2cos??Ϊ
y??4?2sin?? ԭΪ㡢xΪὨϵԲCļ귽̣ ֪A(?2,0),B(0,2)ԲCһM(x,y)?ABMֵ.
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23С10֣ѡ45: ʽѡ
費ʽ|2x?1|?1Ľ⼯Ma,b?M 1ԱȽab?1a?bĴС
22?2??2a?b,,2maxʾAh?max??,֤h??abb??a2
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