(1)由图知:T= -(- )= , 于是w= =2.……………2分 设f1(x)=A sin(2x+j), 将函数f(x)=A sin2x的图象向左平移 , 得f1(x)=A sin(2x+j)的图象,······················································· 3分 则j=2× = , f1(x)=A sin(2x+ ).······································ 4分 将(0,1)代入f1(x)=A sin(2x+ ),易得A=2.····························· 6分 故f1(x)=2sin(2x+ );·································································· 7分 (2)依题意:f2(x)=2sin =-2cos ,······················ 8分 ∴y=2sin -2cos =2 sin .····························· 11分 当2x- =2 + ,即x= + ,k∈ 时,ymax=2 . 此时,x的取值集合为 .………… 12分 |