Why is 3*ln(x) = ln(x^3)3ln(x)=ln(x3)?

1 Answer
Oct 22, 2015

Use the definition of logarithm and basic properties of exponents.
(details below)

Explanation:

Basic definition:
color(white)("XXX")ln(a)=bXXXln(a)=b means e^b=aeb=a

Let s =3 ln(x)s=3ln(x)
color(white)("XXX")rArr ln(x)= s/3XXXln(x)=s3

color(white)("XXX")rArr e^(s/3) = xXXXes3=x

color(white)("XXX")rArr root(3)(e^s) = xXXX3es=x

color(white)("XXX")rArr e^s = x^3XXXes=x3

color(white)("XXX")rArrln(x^3) = sXXXln(x3)=s

color(white)("XXX")rArrln(x^3) = 3ln(x)XXXln(x3)=3ln(x)