Question
Let f(x)= sqrt((x/x+3)-5). Find the domain.
Answers
Steve
you know that x/(x+3) is undefined at x = -3
since √n is defined only for n >= 0, we need
x/(x+3)-5 >= 0
x/(x+3) > 5
x > 5x+15
-15 > 4x
-15/4 > x
So, the domain is all reals less than -15/4. Note that this automatically excludes x = -3.
since √n is defined only for n >= 0, we need
x/(x+3)-5 >= 0
x/(x+3) > 5
x > 5x+15
-15 > 4x
-15/4 > x
So, the domain is all reals less than -15/4. Note that this automatically excludes x = -3.