问题
填空题
数列{an}为等差数列,a3a7=-16,a4+a6=0,则{an}的通项公式为______.
答案
∵a4+a6=0,
∴a5=0,
∵a3a7=-16,
∴(0+2d)(0-2d)=-16,
∴d=±2
∴an=2n-10或-2n+10,
故选An=2n-10或-2n+10,
数列{an}为等差数列,a3a7=-16,a4+a6=0,则{an}的通项公式为______.
∵a4+a6=0,
∴a5=0,
∵a3a7=-16,
∴(0+2d)(0-2d)=-16,
∴d=±2
∴an=2n-10或-2n+10,
故选An=2n-10或-2n+10,