Question

If logb 5=0.41, find logb 12

Answer 1

Determine which one of the following is the correct application of the change of base formula?

a)log3 14= log10 14/3
b)lo4 17= log10 4/ log10 17
c)log8 3= log10 3/log10 8
d)log9 32 = log10 32-log10 9

The change of base formula is as follows:
                                         log to the base 10 of x
log to the base b of x  = ----------------------------------
                                          log to the base 10 of b

Compare this to answer choice C:

c)log8 3= log10 3/log10 8      Here x = 3 and b = 8.  This is the only correct choice.