# Thread: domain of functions 2

1. ## domain of functions 2

how do you find the domain of the function f(x)=x-4 over 2xsquared-x-3

2. Originally Posted by bastropgarl
how do you find the domain of the function f(x)=x-4 over 2xsquared-x-3
this rational function is defined where the denominator is non-zero (you can never divide by zero). So, for what x-values is the denominator equal to zero? (the domain is all x-values but those)

3. so for this question i got the domain as x>4. Is that correct?

4. Originally Posted by bastropgarl
so for this question i got the domain as x>4. Is that correct?
um, no. how'd you get that? do you know what the denominator is?

5. yes i know what the denominator is...but not sure how to find the domain. I got x>4 by trying different numbers into the x place till i got a number > than 0

6. Originally Posted by bastropgarl
yes i know what the denominator is...but not sure how to find the domain. I got x>4 by trying different numbers into the x place till i got a number > than 0
that is not what i told you to do. set the denominator equal to zero and solve. your domain is all x values except the ones you get from doing that. getting something > 0 is not the issue here. i never said it was. we want the denominator to not be zero. this is not an inequality