11.
f(x)=2sinx(sinx+cosx)=2sinx2+2sinxcosx
=根号2sin(2x-π/4)+1
(1)最小正周期T=π
当sin(2x-π/4)=1时,f(x)有最大值,即f(x)=根号2+1
(2)图……=,=自己画咩……
12.
f(x)=sin(x+π/6)+sin(x-π/6)+cosx+a
=2(x+π/6)+a
(1)由于ymax=2+a=1,所以a=-1
(2)因为f(x)大于等于0,所以2sin(x+π/6)-1大于等于0
即sin((x+π/6)大于等于1/2
所以{x|2kπ小于等于x小于等于2π/3+2kπ,k属于Z}