A:you ca
B:can you
C:should you
D:you should
密度(g/cm3)
溶点(℃)
沸点(℃)
溶解性
环已醇
0.96
25
161
能溶于水
已知fx=3cosx+3π2+cosx-3π2+sinx+π+a(a∈R,a为常数).
(1)若f(x)为奇函数,求a的值;
(2)若x∈R,求f(x)的最小正周期;
(3)若x∈0,π2时,f(x)的最大值为4,求a的值.
0.25____ 212 ____