引用第4樓saradomin於2011-02-28 22:33發表的 : [2logx^3-3logx^4] / [log(xy^2)-2log(xy)] =[3(2logx) - 4(3logx) ]/ logx + 2logy - 2logx - 2logy .......
原來還有個大括號嗎-0-...
話時話你岩岩...
引用第4樓saradomin於2011-02-28 22:33發表的 : 2logx^3-3logx^4/log(xy^2)-2log(xy)
=3(2logx) - 4[3log(x/xy^2)] - 2 log(xy) =6logx - (-2)12logy - 2log(xy) =6logx + 24logy - 2logx - 2logy =4logx + 22logy 點解等於-0.5?
log除log時 , x不是不能進入log來自除嗎 ? log x - log y = log(x/y) log x / log y = log x based y |