Saturday 8 February 2014

LOGARITHMS B20

Evaluate Log5(25 x 625).

Solution

= Log5(25 x 625)

= Log525 +  Log5625          (applying the product rule)

= Log552 +  Log554             ( 25= 52 and 625=54 by prime factorization)

= 2Log55 +  4Log55       ( remember  Logaac = cLogaa )

= (2 x 1) +  (4 x 1)          ( remember  Logaa = 1 )

= 2 + 4

= 6

Hence Log3(25 x 625) = 6



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


Evaluate Log5(25 x 15625).




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