Logarithm
- If 10x = 1.73 and log10 1730 = 3.2380, then x is equal to ?
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∵ 10x = 1730/1000
∴ log10x= log101730 - log101000Correct Option: B
∵ 10x = 1730/1000
∴ log10x= log101730 - log101000
⇒ x = 3.2380 - 3
= 0.2380
- The value of logan / logabn is given by ?
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logan / logabn = [( log n / log a) / (log n / log (a.b))]
= log (a.b) / log a
= ( log a + log b) / log a
= 1 + (log b / log a)Correct Option: A
logan / logabn = [( log n / log a) / (log n / log (a.b))]
= log (a.b) / log a
= ( log a + log b) / log a
= 1 + (log b / log a)
= 1 + logab
- The equation logax + loga (1+x)=0 can be written as ?
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logax + loga(1+x) = 0
⇒ logax (x+1) = loga1 (since log 1 = 0)Correct Option: A
logax + loga(1+x) = 0
⇒ logax (x+1) = loga1 (since log 1 = 0)
⇒ x(x +1) = 1
∴ x2 + x - 1 = 0
- The value of $ \frac{\log_{a}{x}}{\log_{ab}{x}} - \log_{a}{b}$ is ?
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∵ loga x = ( logabx) / (logaba)
∴ The given expression = [[(logabx) / (logaba)] / [( logabx )] - ( logab)
= (1/logaba) - logab = logaab - logab = loga(ab/b)
= logaa = 1Correct Option: B
∵ loga x = ( logabx) / (logaba)
∴ The given expression = [[(logabx) / (logaba)] / [( logabx )] - ( logab)
= (1/logaba) - logab = logaab - logab = loga(ab/b)
= logaa = 1
- The value of log23 x log 32 x log34 x log43 is ?
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Given Exp.= log23 x log 32 x log34 x log43
= (log3 / log2) x ( log2 / log3) x (log4 / log3) x (log3 / log4)Correct Option: A
Given Exp.= log23 x log 32 x log34 x log43
= (log3 / log2) x ( log2 / log3) x (log4 / log3) x (log3 / log4) = 1