问题
填空题
数列{an}中,a1=100,an+1=an+2,则a100=______.
答案
∵an+1=an+2(n≥1),
∴an+1-an=2
∴数列{an}是以a1=100为首项,以2为公差的等差数列
∴an=100+(n-1)×2=2n+98
∴a100=200+98=298.
故答案为:298.
数列{an}中,a1=100,an+1=an+2,则a100=______.
∵an+1=an+2(n≥1),
∴an+1-an=2
∴数列{an}是以a1=100为首项,以2为公差的等差数列
∴an=100+(n-1)×2=2n+98
∴a100=200+98=298.
故答案为:298.