29. Which of the following is NOT true about the function f(x)=-2cos(pi×+ pi/3)
? A. The period of f(x) is 2
B.f(x)>0 fot 1/6<×<7/6
C.if × is an element [-1/3,1/6], then f(×) is an element [0,-2]
D. the graph of f(×) is increasing on [2/3,5/3]​