= (radical number 3)/4sin2x+1/4cos2x-3/4 =1/2 ((radical number 3)/2sin2x+1/2cos2x)-3/4 =1/.

So the minimum positive period T=2π/2=π.

(2) Because -π/6

So -π/3

Draw the image of Sinks,

So the minimum value =- 1, and the maximum value =- 1/4.