快遞百科

此文章來自奇摩知識+如有不便請留言告知

標題:

F.4 Logarithmic functions

發問:

圖片參考：http://imgcld.yimg.com/8/n/HA07887627/o/701111170101913873402822.jpg 想問Q31,32,41,42,55(!)

最佳解答:

hello, can you just show (and enlarge) those questions you need.. its hard to see the base values... 2011-11-18 12:19:28 補充： 31. (please upload another clear pic) 32. the upper part: log(6^1/2) - log(12^1/2) = (1/2)log(6/12) = (1/2) log (1/2) the lower part: log(6^1/3) - log(24^1/3) = (1/3)log(6/24) = (1/3) log (1/4) = (2/3) log (1/2) thus, [(1/2) log (1/2)] / [(2/3) log (1/2)] = ... (by yourself) 41. take log of L.H.S. = log8 + (2x+5)log6 = (2x)log6 + log8 + 5log6 take log of R.H.S. =(3x-4)log7 = (3x)log7 - 4log7 (2x)log6 + log8 + 5log6 = (3x)log7 - 4log7 x[3log7 - 2log6] = 4log7 + log8 + 5log6 x = .... (by yourself) 42. take log of L.H.S. = xlog3 + (x+3)log4 = x[log3+log4] + 3log4 take log of R.H.S. =(x+2)log5 = xlog5 + 2log5 xlog12 + log64 = xlog5 + log25 x[log12 - log5] = log25 - log64 x log (12/5) = log (25/64) x = .... (by yourself) 55a. W = 4(0.4)^t log0.4W = log0.44 + t log0.40.4 where log0.40.4 = 1 log0.4W = log0.44 + t = t - 1.513 55b. from the graph put x = 3, y = -1.2 thus, log0.43 = -1.2 when W = 3, and from 55a log0.4W = t - 1.513 => log0.4 3 = t - 1.513 => -1.2 = t - 1.513 => t = 0.313 min.

其他解答:A9A39959EDCC7BE3