Saturday 8 February 2014

LOGARITHMS B18


Evaluate Log3(729 x 81).

Solution

= Log3(729 x 81)

= Log3729 +  Log381          (applying the product rule)

= Log336 +  Log334     ( 729= 36 and 81=34 by prime factorization)

= 6Log33 +  4Log33       ( remember  Logaac = cLogaa )

= (6 x 1) +  (4 x 1)          ( remember  Logaa = 1 )

= 6 + 4

= 10


Hence Log3(729 x 243) = 10

TRY THIS....................


Evaluate Log3(6561 x 81).

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