温故知新2.化简:.1)1(4)1(6)1(4)1(234xxxx1532)1()1()1()1(xxxx3.展开式中含x3项的系数为___________。52()2xx的有理项1.求:1820奎屯王新敞新疆n2)x2x(4.的展开式中,第五项与第三项的二项式系数之比为14:3,求展开式的常数项2r510r10rr2r10r101rxC)2()x2()x(CT温故知新5.nx)12(2展开式的各项系数和为______;16.展开式的二项式系数之和为128、那么展开式的项数是;各项系数之和为:nyx)7(7.nxxx)1()1()1(2的所有二项式的各项系数和是;2n+1-28.0177888)2(axaxaxax则______1678aaaa-255温故知新1、计算0.9973的近似值(精确到0.001)0.9973=(1-0.003)3=1−3·0.003+3·0.0032−0.0033≈1−3·0.003=0.991近似计算问题练习:求2.9986的近似值(精确到小数点后第三位);2.9986=(3-0.002)6=36−6·35·0.002+15·34·0.0022−20·33·0.0023+…≈36−6·35·0.002+15·34·0.0022=729−2.916+0.00486≈726.089求:112004被10除的余数。110101010)110(20042004200320042003120042004020042004MCCCC余数与整除问题练:①5510被8除的余数.②5710被8除的余数.求证:5555+1能被8整除;因为5555+1=(56−1)55+1=56·M−1+1=56·M,所以5555+1能被8整除.余数与整除问题3、求证:42n+1+3n+2能被13整除;42n+1+3n+2=4·16n+9·3n=4·(13+3)n+9·3n=4·13·M+4·3n+9·3n=4·13·M+13·3n所以42n+1+3n+2能被13整除.题组四(求值、等式与不等式证明问题)5105410631072108110910333333)2(CCCCC证明:1055845635425215222221)1(CCCCC求值:10243333910810271036104CCCC⑶求证:)2,)(2(231nNnnnn