-Is this your uncle?
-No, __________.
A:he is
B:she is
C:he isn't
D:she isn't
已知等比数列{an}的前n项和为Sn,an>0,a1=23,且﹣3a2,1a3,1a4成等差数列.
求数列{an}的通项公式
用计算器计算并填空:
(1)9×9+7=____,(2)98×9+6=____,
(3)987×9+5=____,(4)9876×9+4=____,
…
(5)观察计算结果,用你发现的规律填空:98765432×9+0=____.
甲、乙两辆汽车都做匀速直线运动,其路程S随时间t变化的图象如图所示.从图象可知,____ 车的速度大;5S内乙车通过的路程是____ m.