#log 1 = x color(white)("dd") x=?#

2 Answers
Feb 26, 2018

#x=0#

Explanation:

The concept is:

#log_(base)power="index"#

#power=base^"index"#

#log_(base)1=x#

#1=base^"index"#

Anything raised to the power is zero

#"index"=0#

#x=0#

Feb 26, 2018

If #log(1)=x# then #x=0#

A lesson about logs given in the explanation part of the page.

Explanation:

log to base 10 is written as #log_10#.

However, this is the standard form so people tend to leave out the 10 in #log_10# and just write #log#

Ok! We have two choices.

Choice 1. Look it up using a calculator
#color(white)("ddddddd")#In the old days it was obtained from a log book

#color(white)("ddddddd")#By calculator I get: #log_10=0#

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Choice 2. Consider the structure of what a log actually is.
#color(white)("ddddddd")#You know about #3^2#.
#color(white)("ddddddd")#Well the 2 bit is an index. (indices or powers).

Logs are looking at 'powers' but in a different way

Another way of writing #log_10(1)=x" is "10^x=1#

So #x# is the 'power' applied to 10 and this gives the answer 1.

Using examples: it is known that #2^0 = 0,color(white)("d")5^0=1, color(white)("d")365^0=1#

So from this #ubrace(10^0=1)# which is why #log_10(1)=0#
#color(white)("dddddddddd.d")darr#
#color(white)("ddddddddd")10^x=1#