若f(n)=sinnπ6,f(1)+f(3)+f(5)+…+f(101)=______.-数学

题目简介

若f(n)=sinnπ6,f(1)+f(3)+f(5)+…+f(101)=______.-数学

题目详情

f(n)=sin
6
,f(1)+f(3)+f(5)+…+f(101)
=______.
题型:填空题难度:中档来源:不详

答案

因为y=sinx的周期是2π,
所以f(1)+f(3)+f(5)+…+f(11)
=sinclass="stub"π
6
+sinclass="stub"3π
6
+sinclass="stub"5π
6
+sinclass="stub"7π
6
+sinclass="stub"9π
6
+sinclass="stub"11π
6

=class="stub"1
2
+1+class="stub"1
2
-class="stub"1
2
-1-class="stub"1
2
=0,
∴f(1)+f(3)+f(5)+…+f(101)
=8×(sinclass="stub"π
6
+sinclass="stub"3π
6
+sinclass="stub"5π
6
+sinclass="stub"7π
6
+sinclass="stub"9π
6
+sinclass="stub"11π
6
)+sinclass="stub"π
6
+sinclass="stub"3π
6
+sinclass="stub"5π
6

=sinclass="stub"π
6
+sinclass="stub"3π
6
+sinclass="stub"5π
6

=class="stub"1
2
+1+class="stub"1
2
=2.
故答案为:2.

更多内容推荐