How do you find the domain for f(x) = 1/(sqrt(3-2x))f(x)=132x?

1 Answer
Jun 4, 2016

Whenever you are dealing with domain/range of a function that involves a radical, you need to set the radical to the following: x - b >= 0xb0, since a radical is undefined in the real number system if x < 0x<0. Once you have set it in the way explained above you solve the resulting inequality.
sqrt(3 - 2x) >= 032x0

(sqrt(3 - 2x))^2 >= 0^2(32x)202

3 - 2x >= 032x0

3 >= 2x32x

3/2 >= x32x

Interestingly, this is also a rational function. Therefore, we must determine any vertical asymptotes. Vertical asymptotes in a rational function can be found by setting the denominator to 0 and solving for x. Doing this:

sqrt(3 - 2x) = 032x=0

(sqrt(3 - 2x))^2 = 0^2(32x)2=02

3 - 2x = 032x=0

x = 3/2x=32

Therefore, x != 3/2x32 in this function.

In the domain statement, we can say that x < 3/2x<32, because we had no choice but to remove the x = 3/2x=32, since this was the equation of the vertical asymptote.

Hopefully this makes sense!