If f ( x ) = x + 6 and g ( x ) = x − 1 x + 9 , find the domain of g ( x ) f ( x ) .
This section requires Javascript.
You are seeing this because something didn't load right. We suggest you, (a) try
refreshing the page, (b) enabling javascript if it is disabled on your browser and,
finally, (c)
loading the
non-javascript version of this page
. We're sorry about the hassle.
The domain of f ( x ) is x ∈ [ − 6 , ∞ ) . The domain of g ( x ) is x ∈ ( − ∞ , 1 ) ∪ ( 1 , ∞ ) . Therefore, the domain of g ( x ) f ( x ) is x ∈ [ − 6 , 1 ) ∪ ( 1 , ∞ ) .
Problem Loading...
Note Loading...
Set Loading...
We know:
Domain of ( g f ) ( x ) = Domain of f ( x ) ∩ Domain of g ( x )
The domain of f ( x ) :
Domain of f ( x ) ⟹ x + 6 x x ≥ 0 ≥ − 6 ∈ [ − 6 , ∞ )
The domain of g ( x ) :
Domain of g ( x ) ⟹ x − 1 x + 9 x ∈ R − { 1 } ( x − 1 ) = 0 Not defined for x-1
Now intersection of values is:
x ∈ [ − 6 , ∞ ) ∩ x ∈ R − { 1 } ⟹ x ∈ [ − 6 , ∞ ) − { 1 } x ∈ [ − 6 , 1 ) ∪ ( 1 , ∞ )