(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=2sin.····························· 11分 当2x-=2+,即x=+,k∈时,ymax=2. 此时,x的取值集合为.………… 12分 |