Hey guys. I was doing my math homework and ran into some trouble with numbers 42 and 43, both are attached in a picture. I could find the rational functions just fine, but I did not quite understand part b. What does it mean for a function to be defined? The answer for part b of number 43 was all real numbers greater than zero, but I don't understand why? Here is what I got for part a for both numbers:
42.
a. R(x)= (6x+4)/(2x^2 +3x+1)
43.
a. R(x)= 2/x
If you could please help, that would be great. The two math problems have been attached.