f(x)=f(2π-x)=f(π-(x-π))=-f(x-π)
即f(x)=-f(x-π)
再次利用上式,f(x)=-f(x-π)=f(x-2π)
所以T=2π
f(59π/11)=f(15π/11+4π)=f(15π/11)=f(2π-7/11)=f(7π/11)=f(π-4π/11)=-f(4π/11)=——16π^2/121.
由题意:f(59/11π)=f(2π-59/11π)=f(-37/11π)=-f(48/11π)=-f(-26/11π)=f(37/11π)=f(-15/11π)=-f(26/11π)=-f(-4/11π)=f(15/11π)=f(7/11π)=-f(4/11π)
因为4/11π∈[0,π/2]
所以原式=-f(4/11π)=-16/121*π²
11π/59∈[0,π/2]
据题意得
f(11π/59)=(11π/59)^2
其实不难就是不停地套这两个式子!
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