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Tutors Answer Your Questions about logarithm (FREE)
Question 17622: I need help solving this problem:
(0.75)^n < 0.000125 where n is an integer.
I'm not supposed to use a calculator and i'm supposed to use log tables. Till now, i've taken log on both sides:
n log(0.75) < log 0.000125 . This is where i'm getting stuck. Please help.
Thanks a lot
Click here to see answer by venugopalramana(3286)   |
Question 13926: I am not sure how to go about this, it was listed in a solution and there is alot of assumptions on the readers behalf or atleast mine.
nlog(base4)n=log(base2)4*nlog(base2)n=2nlog(base2)n
There is a base change from 4 to 2 and I am getting hung up on this one.
nlog(base4)=n(log(base 2)n/log(base 2)4)= n(log(base 2)n-log(base 2)4)=
nlog(base 2)n - nlog(base 2)4
is what I have tried and they don't look the same. Could you please help.
Thanks in advance.
Michael
Click here to see answer by MelanieBCC(40)  |
Question 18448: I am trying to use logarithms to find the fifth root of 37.
The procedure I used gives me the wrong answer.What have I done wrong?
To get the fifth root of 37 I did the following:
1)Designated the fifth root of 37 as 37^1/5
2)Looked up 3.7 in the common log table to get .5682
3)Divided .5682 by 5 to get .1137
4)Found the antilog of .1137 to be about 1.30
But this is the wrong answer. I know this because this problem was worked out somewhere else and the correct answer is 2.0589. To get this answer, the following steps were made:
antilog(log(37)/5=
antilog(3.6109/5)=
antilog(.7221)=
2.0589
In terms of the latter correct solution, I do not understand how the 3.6109 number is derived. Also, I assume that the antilog I found is incorrect if the antilog times .7221 is the answer of 2.0589.
I would really appreciate knowing the nature of my errors and how this problem was solved correctly. I imagine I need a more basic explanation concerning the necessary steps and procedures about how to solve this problem in terms of the corrent explanation.
Click here to see answer by venugopalramana(3286) |
Question 19124: I am not sure exactly where to start on this homework problem. I would like you to please help me with this problem, so maybe I can get the rest of my homework.
Use log base 5 of 2=0.4307 and log base 5 of 3=0.6826 to approximate the value of each expression which is log base 5 of 9.
It is kind of difficult and if you understand what I am asking, please help me out on this.
Click here to see answer by mmm4444bot(95) |
Question 20541: What is the value of U in the equation; log (3u+14) - log5 = log2u? I tried to work it myself and got an answer of -9, but I don't think it's right because there was a similar problem in my book but they didn't show you how to do it. Can you please walk me through it?
Click here to see answer by AnlytcPhil(958) |
Question 20542: 4log x + log5 = log405 What is the value of X in this logarithm? When I tried to work it I simplified the equation to logx^4 + log5 = log405. Then I subtracted x from both sides and was left with logx^4 = 400. Please walk me through this because even if I am doing it correctly I don't know what to do next.
Click here to see answer by AnlytcPhil(958) |
Question 20540: What is the value of W? log 48 - logw = log4 When I did the equation the first time I got zero, but the second time I got 44. What I did was cancel out the log on both sides and was left with 48-w=4. When I solved I got 44. Can you please help me and tell me if my answer is correct or not? Thanks
Click here to see answer by Earlsdon(4898) |
Question 20730: Can anyone help solve this?
1 - logx = log(3x-1)
I tried:
1 - logx = log 3x - log 1
1 = logx + log 3x - log 1
1 = log4x - log 1
I also tried:
1 - logx = log(3x-1)
divide both sides by log
1-x = (3x-1)
2 - x = 3x
2 = 4x
1/2 = x
Or:
1 - logx = log(3x-1)
1 - 10 = log3x - log
-9 = 3logx - log
-9 = 3(10) - log
-9 = 30 - log
-39 = -log
The teacher's answer is 2
Can anyone help?
Thanks,
Sandy
Click here to see answer by Earlsdon(4898) |
Question 20723: I'm about to go crazy over here trying to figure out this problem!!! Can you PLEASE tell me the value of M in the equation; log (3m+7) - log(m+4) = 2log6 - 3log3. I tried to solve it, but I got stuck. I got as far as log(3m+7) - log(m+4) = log36 - log27. PLEASE HELP ME!!!
Click here to see answer by askmemath(368) |
Question 20728: Can anyone please help with the following problem?
In * sqrt of (x^2 + x over 6) = 0
I tried:
In (x^2 +x over 6)^1/2 = 0
1/2 In x^2 - 1/2 In 6 = 0
But I don't know where to go from there!
The teacher's answer is (-3,2)
Thanks,
Sandy
Click here to see answer by kapilsinghi(68) |
Question 21192: Good evening,
I need your help to solve for the exponent t. 5^t = 7^(t+1). I started with t log 5 = (t+1) log 7. So, I tried deducting (t+1) from both sides and then divide log 7 from both sides, but didn't really understand.
Please help.
Joanna
Click here to see answer by longjonsilver(2297)  |
Question 21493: Please help me solve this....
In September 1998 the population of the country of West Goma in millions was modeled by f(x)=17.5e^0.0006x. At the same time the population of East Goma in millions was modeled by g(x)=14.1e^0.0187x. In both formulas x is the year, where x=0 corresponds to September 1998. Assuming these trends continue, estimate the year when the population of West Goma will equal the population of East Goma.
The answer is 2010 but i have tried every method possible to come up with this answer please help......
Click here to see answer by mmm4444bot(95) |
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Older solutions: 1..45, 46..90, 91..135, 136..180, 181..225, 226..270, 271..315, 316..360, 361..405, 406..450, 451..495, 496..540, 541..585, 586..630, 631..675, 676..720, 721..765, 766..810, 811..855, 856..900, 901..945, 946..990, 991..1035, 1036..1080, 1081..1125, 1126..1170, 1171..1215, 1216..1260, 1261..1305, 1306..1350, 1351..1395, 1396..1440, 1441..1485, 1486..1530, 1531..1575, 1576..1620, 1621..1665, 1666..1710, 1711..1755, 1756..1800, 1801..1845, 1846..1890, 1891..1935, 1936..1980, 1981..2025, 2026..2070, 2071..2115, 2116..2160, 2161..2205, 2206..2250, 2251..2295, 2296..2340, 2341..2385, 2386..2430, 2431..2475, 2476..2520, 2521..2565, 2566..2610, 2611..2655, 2656..2700, 2701..2745, 2746..2790, 2791..2835, 2836..2880, 2881..2925, 2926..2970, 2971..3015, 3016..3060, 3061..3105, 3106..3150, 3151..3195, 3196..3240, 3241..3285, 3286..3330, 3331..3375, 3376..3420, 3421..3465, 3466..3510
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