domain is all the numbers you can use for x, it's the input
range is the numbers you get from inputting the domain, it's te output
we can use all real numbers because no square roots of negatives or division of zero occur
domain is all real numbers
notice that when x goes to positive infinity, f(x) goes to positive infinity
when x goes to negative inifnity, f(x) goes to positive inifinty
but, as x approaches 4, the value of f(x) approaches 0
the lowest point on range is 0 and max is negative infinity
domain=all real numbers
range= from 0 to infinity
