(1)2x-π/3=kπ+π/2,求得对称轴x=1/2kπ+5π/12(k为整数);
(2)函数在【-π/12,11π/12】单调递增,则
x=π/12时,f(x)min=-1/4;
x=5π/12时,f(x)max=1/2.