The domain of y = -3x – 1 is all real numbers.

(The domain is all values that x can take on).

The range of y = -3x – 1 is all real numbers.

This means y can equal any number.

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y = sqrt(x + 1) – 3

If x < 1, you would be taking the square root of a negative number, which is imaginary. Therefore, x has to be greater than 1. So, the domain of y = sqrt(x + 1) - 3 is: x ≥ 1 or {x | x ≥ 1} The range of y = sqrt(x + 1) - 3 is: y ≥ -3 If x ≥ 1, the lowest value that y can be is -3. The upper limit of y is infinity. Good luck in your studies, ~ Mitch ~ P.S. - Good websites to understanding the domain and range are: http://www.freemathhelp.com/domain-range.html http://www.purplemath.com/modules/fcns2.htm http://www.intmath.com/Functions-and-graphs/2a_Domain-and-range.php http://mathdemos.gcsu.edu/mathdemos/domainrange/domainrange.html http://www.sparknotes.com/testprep/books/newsat/chapter19section13.rhtml

for example:

y = square root of x

now x must be 0 or greater because the squareroot of a negative number does not exist. This mean that the domain must be >= 0 (greater or equal to zero.)

But because x >= 0 this means that y can never be negative and must also be >= 0 , so here the range in also >= 0

the range is of course y>=-3