???a2?b2?c2?0.5A
5．解：f??x?0.5?f?2x? x 0exp?x2?t2?f?t?dt?x?0.5?f?2x?f?x0.5?
?f??1??3f?1???1 二、解：a111n??0max?an?1,x?dx??0an?1dx?an?1,即{an}单调增且a1?2?1, 设0?an?1,则0?an?1??10max?an,x?dx??10dx?1,即{an}有界。
可知{aa1n}收敛记其极限为a,有a??10max?a,x?dx??0adx??axdx??1?a2?/2 a?1 三、解：V??0.5?r2ds??0.5?t301?4t2dt???0.5004t21?4t2d?4t2?1?/32
??232?1?t?1?tdt????2t2.5?2t1.5??232?53?1??120?2?1?
四、证明：
x???exp??t2? ???t2? ???t2?x??2??dt?? xxexp???2??dt?? xtexp???2??dt?exp??x2???2?
?五、证明：tanx?x,?tanx???1?tan2x?1?x2?tanx?x?x3/3
易知 sinx?x?x3/6 ?tan2x?2sin2x?3x2,.
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