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题型:填空题 题类:常考题 难易度:普通
2015-2016学年河南省南阳一中高二下学期开学数学试卷(理科)
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则12+22+…+n2=(其中n∈N*).
通过观察上述两等式的规律,请你写出一般性的命题,并给出的证明.
(sin )﹣2+(sin )﹣2= ×1×2;
(sin )﹣2+(sin )﹣2+(sin )﹣2+sin( )﹣2= ×2×3;
(sin )﹣2+(sin )﹣2+(sin )﹣2+…+sin( )﹣2= ×3×4;
(sin )﹣2+(sin )﹣2+(sin )﹣2+…+sin( )﹣2= ×4×5;
…
照此规律,
(sin )﹣2+(sin )﹣2+(sin )﹣2+…+(sin )﹣2={#blank#}1{#/blank#}.
S1=1
S2=2+3=5
S3=4+5+6=15
S4=7+8+9+10=34
S5=11+12+13+14+15=65
S6=16+17+18+19+20+21=111
S7=22+23+24+25+26+27+28=175
可得S1+S3+S5+…+S2n﹣1={#blank#}1{#/blank#}.
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