Question #a2dcd

2 Answers
Feb 27, 2016

If: #log_y(x) = 1# => then: #x=y#
but if: #log_y(1)=x# => then: #x=0#

Explanation:

Definition of logarithm:
For #x>0#
if: #log_a(x)=y#
then: #x=a^y#

For #x<=0# :
#log_a(x)# is "Undefined"

Feb 27, 2016

#x=10#
(what you "knew" was incorrect)

Explanation:

Two points:
[1]#color(white)("XXX")# the default base for #log# is #10#: #log x# means #log_10 x#
[2]#color(white)("XXX")log_b a = k hArr b^k=a#

From [1]
#color(white)("XXX")log x =1# is the same as #log_10 x = 1#

From [2]
#color(white)("XXX")log_10 x = 1 hArr 10^1 = x#

Therefore
#color(white)("XXX")x=10^1 = 10#