How do you find the domain of #ln(x^2-4)#?

1 Answer
Dec 8, 2016

Answer:

The domain of #f(x)# is #(-oo,-2) uu (+2,+oo)#

Explanation:

#f(x)= ln(x^2-4)#

Since #lnx# is defined for #x>0#
#f(x)# is defined for #x^2-4 >0#

Hence: #f(x)# is defined for #absx> 2#

The domain of a function is the set of input values #(x)# for which the function #f(x)# is defined.

Therefore the domain of #f(x)# in this example is: #(-oo,-2) uu (+2,+oo)#

This can be seen by the graph of #f(x)# below.
graph{ln(x^2-4) [-10, 10, -5, 5]}