y=log(5+4x-x^)的值域是 1/3

熱心網友

y=log(5+4x-x^)的值域是0＜5+4x-x^=-(x^-4x+4)+9=-(x-2)^+9≤9∴當0＜底數＜時1，y=log(5+4x-x^)的值域是[log9,+∞)當底數＞1時，y=log(5+4x-x^)的值域是(-∞,log9]