Q. Find the numerical value of the log expression.loga=−6logb=−9logc=−12loga43b4c7Answer:
Understand Given Values: Understand the given logarithmic values and the expression to evaluate.We are given:loga=−6logb=−9logc=−12We need to find the value of:log(a43b4c7)Let's start by simplifying the expression using logarithmic rules.
Apply Quotient Rule: Apply the quotient rule of logarithms to the expression.The quotient rule states that log(yx)=log(x)−log(y).So, log(a43b4c7)=log(3b4c7)−log(a4)
Apply Power Rule: Apply the power rule of logarithms to the expression.The power rule states that log(x(n))=n⋅log(x).So, log(a(4))=4⋅log(a)Since we know log(a)=−6, we can substitute to get:log(a(4))=4⋅(−6)=−24
Apply Cube Root: Apply the cube root as a power of 1/3 to the logarithm.The cube root of a number can be expressed as the number raised to the power of 1/3.So, log(3b4c7)=log((b4c7)1/3)Using the power rule again, we get:log((b4c7)1/3)=(1/3)⋅log(b4c7)
Apply Product Rule: Apply the product rule of logarithms to the expression.The product rule states that log(xy)=log(x)+log(y).So, (31)⋅log(b4c7)=(31)⋅(log(b4)+log(c7))
Apply Power Rule: Apply the power rule to the individual logarithms.Using the power rule again:log(b4)=4×log(b)log(c7)=7×log(c)Since we know log(b)=−9 and log(c)=−12, we can substitute to get:log(b4)=4×(−9)=−36log(c7)=7×(−12)=−84
Substitute Values: Substitute the values back into the expression.Now we have:(\frac{\(1\)}{\(3\)}) \times (\log (b^{\(4\)}) + \log (c^{\(7\)})) = (\frac{\(1\)}{\(3\)}) \times (\(-36 + (−84))= (\frac{1}{3}) \times (−120)= −40
Combine Results: Combine the results to find the final value of the original expression.We have:log(a43b4c7)=log(3b4c7)−log(a4)=−40−(−24)=−40+24=−16
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