等差数列{an}中,a3+a5=24,a2=3,则a6=_.
问题描述:
等差数列{an}中,a3+a5=24,a2=3,则a6=______.
答
∵a3+a5=24,a2=3
∴
2a1+6d=24
a1+d=3
解方程可求,a1=−
,d=3 2
9 2
∴a6=a1+5d=−
+3 2
=21.45 2
故答案为:21