Logarithm Properties Math Example 2

Follow the full solution, then compare it with the other examples linked below.

Example 2

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Condense 2lnโกxโˆ’12lnโก(x+1)+3lnโกy2\ln x - \frac{1}{2}\ln(x + 1) + 3\ln y into a single logarithm.

Solution

  1. 1
    Apply the power rule: lnโกx2โˆ’lnโก(x+1)1/2+lnโกy3\ln x^2 - \ln(x+1)^{1/2} + \ln y^3.
  2. 2
    Apply the product rule to the positive terms: lnโก(x2y3)โˆ’lnโกx+1\ln(x^2 y^3) - \ln\sqrt{x+1}.
  3. 3
    Apply the quotient rule: lnโก(x2y3x+1)\ln\left(\frac{x^2 y^3}{\sqrt{x+1}}\right).

Answer

lnโก(x2y3x+1)\ln\left(\frac{x^2 y^3}{\sqrt{x+1}}\right)
Condensing is the reverse of expanding: use the power rule first to move coefficients into exponents, then combine with the product and quotient rules.

About Logarithm Properties

The three fundamental rules of logarithms: the product rule logโกb(xy)=logโกbx+logโกby\log_b(xy) = \log_b x + \log_b y, the quotient rule logโกbโ€‰โฃ(xy)=logโกbxโˆ’logโกby\log_b\!\left(\frac{x}{y}\right) = \log_b x - \log_b y, and the power rule logโกb(xn)=nlogโกbx\log_b(x^n) = n\log_b x.

Learn more about Logarithm Properties โ†’

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