已知,则f(1)+f(2)+f(3)+…+f(2009)=________.
网友回答
解:由,
则f(1)+f(2)+f(3)+…+f(2009)
=1+sin+1+sinπ+1+sin+1+sin2π+1+sin+…+1+sin
=2009+(sin+sinπ+sin+sin2π)+(sin+sin3π+sin+sin4π)+…+(sin+sin1003π+sin+sin1004π)
+sin=2009+(sin+sinπ+sin+sin2π)+(sin+sinπ+sin+sin2π)+…+(sin+sinπ+sin+sin2π)+sin
=2009+0+0+…+0+sin(2×502π+)
=2009+1
=2010
故