函数f(x)=sin^2(x+pi/12)+cos^2(x-pi/12)的最大值

f(x)=sin²(x+π/12)+cos²(x-π/12)=1-cos²(x+π/12)+cos²(x-π/12)=1+[cos(x-π/12)+cos(x+π/12)][cos(x-π/12)-cos(x+π/12)]=1+(cosx cosπ/12 + sinx sinπ/12 + cosx cosπ/12 -sinx sinπ...