问题
填空题
已知f(x)=1+sin
|
答案
由f(x)=1+sin
x,π 2
则f(1)+f(2)+f(3)+…+f(2009)
=1+sin
+1+sinπ+1+sinπ 2
+1+sin2π+1+sin3π 2
+…+1+sin5π 2 2009π 2
=2009+(sin
+sinπ+sinπ 2
+sin2π)+(sin3π 2
+sin3π+sin5π 2
+sin4π)+…+(sin7π 2
+sin1003π+sin2005π 2
+sin1004π)2007π 2
+sin
=2009+(sin2009π 2
+sinπ+sinπ 2
+sin2π)+(sin3π 2
+sinπ+sinπ 2
+sin2π)+…+(sin3π 2
+sinπ+sinπ 2
+sin2π)+sin3π 2 2009π 2
=2009+0+0+…+0+sin(2×502π+
)π 2
=2009+1
=2010
故答案为:2010