Math Definition...Help

Domain is the set of possible inputs, or x values. Range is the set of possible outputs, or y values.

Example being {(1,2) (3,4) (5,6)}

Domain: 1,3,5
Range: 2,4,6

Okay but...
Does the given definition of domain and range also apply to functions?

For example:

What is the domain and range of f(x) = x + 4/x - 3?

yup, sure does.

With functions, for every input, there's exactly one output (otherwise it's not a function)
So you need to find what inputs (x) are possible and which outputs (y) are possible


for the example you gave: f(x) = (x+4)/(x-3)

What input makes this undefined? (basically, what value of x makes the denominator equal to zero?) in this case, it's three.

So the domain would be all real numbers INEQUAL to three


Moving on to range

set the equation equal to y y = (x+4)/(x-3) and solve for x

y(x-3) = (x+4)

yx - 3y = x+4

yx = x + 4 + 3y

yx - x = 4+3y

x(y-1) = 4+3y

x = (4+3y)/(y-1)

do the same thing as with finding domain- what y value makes the denominator equal to zero? in this case, 1
So range is all real numbers INEQUAL to 1

this is the kind of thing that just takes practice, if you need me to clear anything up, I'd be more than happy to help.

Got it
Got it. Thank you all for your help.