LOGARITHMS B14

Evaluate Log₂(128 x 256).

Solution

= Log₂(128 x 256)

= Log₂128 +  Log₂256          (applying the product rule)

= Log₂2⁷ +  Log₂2⁸             ( 128= 2⁷ and 256=2⁸ )

= 7Log₂2 +  8Log₂2       ( remember  Log_aa^c = cLog_aa )

= (7 x 1) +  (8 x 1)          ( remember  Log_aa = 1 )

= 7 + 8

= 15

hence Log₂(128 x 256) = 15

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

Evaluate Log₂(128 x 4).