Question #55b9f

2 Answers
Aug 27, 2017

The domain is restricted by the condition that the denominator is not equal to 0.

Explanation:

Division by 0 would cause the expression be undefined, therefore, the domain restrictions can be found by solving the equation:

#x^2 + 6x - 16 = 0 " [1]"#

and then stipulating that the x cannot equal these values.

Factor equation [1]:

#(x -2)(x + 8) = 0#

This separates into two equations:

#x -2 = 0# and #x + 8 = 0#

Simplify both:

#x = 2# and #x = -8#

Therefore, the domain restrictions are #x!=2# and #x!=-8#

Aug 27, 2017

#(-oo, -8) uu (-8,2) uu (2,oo)#

Explanation:

The denominator of the function cannot be zero. To find the restrictions on the domain, find the values of #x# which would make the denominator #0#.

#x^2 + 6x - 16 != 0#

#(x+8)(x-2) != 0# #-># factor

#x+8 != 0# and #x-2 != 0#

#x !=-8# and #x !=2#

So, the domain of the function is all real numbers, where #x != -8,2#. We can write this in interval notation as #(-oo, -8) uu (-8,2) uu (2,oo)#.

We can verify this by graphing the function. As you can see, there are vertical asymptotes at #x=-8# and #x=2#.

graph{(x^2+3)/(x^2 + 6x - 16) [-17.96, 14.08, -6.02, 10.01]}