Solve the Product: log₄6 × log₆9 × log₉4 Logarithm Chain

Question

log46×log69×log94= \log_46\times\log_69\times\log_94=

Video Solution

Solution Steps

00:00 Solve
00:04 We'll use the formula for multiplication of logarithms
00:10 We'll switch between the bases of the logarithms
00:17 We'll use this formula in our exercise
00:29 We'll use this formula again in the exercise and switch between these bases
00:44 We'll calculate each logarithm separately
00:48 And this is the solution to the question

Step-by-Step Solution

To solve this problem, we need to recognize that the expression log46×log69×log94\log_46 \times \log_69 \times \log_94 fits the identity of logarithms: logab×logbc×logca=1\log_a b \times \log_b c \times \log_c a = 1.

Let us examine the expression:

  • The first term is log46\log_46, where a=4a = 4 and b=6b = 6.
  • The second term is log69\log_69, where b=6b = 6 and c=9c = 9.
  • The third term is log94\log_94, where c=9c = 9 and a=4a = 4.

Notice how log46\log_46, log69\log_69, and log94\log_94 correspond respectively to logab\log_a b, logbc\log_b c, and logca\log_c a. Thus, the entire expression matches the multiplication identity of logarithms: logab×logbc×logca=1\log_a b \times \log_b c \times \log_c a = 1.

Therefore, the value of the expression log46×log69×log94\log_46 \times \log_69 \times \log_94 is 11.

Answer

1 1


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