已知f(x)=1+sinπ2x,则f(1)+f(2)+f(3)+…+f(2009)=______.-数学

题目简介

已知f(x)=1+sinπ2x,则f(1)+f(2)+f(3)+…+f(2009)=______.-数学

题目详情

已知f(x)=1+sin
π
2
x
,则f(1)+f(2)+f(3)+…+f(2009)=______.
题型:填空题难度:偏易来源:不详

答案

f(x)=1+sinclass="stub"π
2
x

则f(1)+f(2)+f(3)+…+f(2009)
=1+sinclass="stub"π
2
+1+sinπ+1+sinclass="stub"3π
2
+1+sin2π+1+sinclass="stub"5π
2
+…+1+sinclass="stub"2009π
2

=2009+(sinclass="stub"π
2
+sinπ+sinclass="stub"3π
2
+sin2π)+(sinclass="stub"5π
2
+sin3π+sinclass="stub"7π
2
+sin4π)+…+(sinclass="stub"2005π
2
+sin1003π+sinclass="stub"2007π
2
+sin1004π)
+sinclass="stub"2009π
2
=2009+(sinclass="stub"π
2
+sinπ+sinclass="stub"3π
2
+sin2π)+(sinclass="stub"π
2
+sinπ+sinclass="stub"3π
2
+sin2π)+…+(sinclass="stub"π
2
+sinπ+sinclass="stub"3π
2
+sin2π)+sinclass="stub"2009π
2

=2009+0+0+…+0+sin(2×502π+class="stub"π
2

=2009+1
=2010
故答案为:2010

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