(Ⅰ)由题意得
························· 2分 因为cosA≠0, ···························· 3分 所以tanA="1." ····························· 4分 (Ⅱ)由(Ⅰ)知tanA=1得
······················· 5分 = ························ 6分 = ····················· 7分 因为x R,所以 .······················ 8分 当 时,f(x)有最大值 ,··················· 10分 当sinx=-1时,f(x)有最小值-2,··················· 11分 所以所求函数f(x)的值域是 ·················· 13分 |