题目
已知向量,,函数,(x∈R)。 (1)求函数的最大值及其相对应的x值; (2)求函数的单调增区间. 答案:解:(1) 因为向量,,函数,(x∈R) 所以=4()+2 = 4+ 2 = 2cos2x + 2 2+ 2 = 4sin(2x) + 4 当2x= +2kπ,k∈Z时,sin(2x)=,函数= 8 所以= 8,此时x= kπ,k∈Z (2)令t=2x,则y=4sint + 4,其单调递增区间为: [He would rather __________ at home because it's raining hard outside.A.stayB.to stayC.stayingD.stays