How do you determine the domain of a function ?

Let y = f(x) be a function with an independent variable x and a dependent variable y.

If a function f provides a way to successfully produce a single value y using for that purpose a value for x then that

chosen x-value is said to belong to the domain of f. If there is a requirement that a y-value produced by a function

must be a real number, the following conditions are commonly checked:

1. Denominators cannot equal 0.

2. Radicands (expressions under a radical symbol) of even roots (square roots, etc)  

cannot have a negative value.

3. Logarithms can only be taken of positive values.

4. In word problems physical or other real-life restrictions might be imposed, e.g. time is  

nonnegative, number of items is a nonnegative integer, etc.

the domain is a set of all possible numbers inputs for that function, THe range is all the possible output numbers

i hope this helps

answer: it is d

step-by-step explanation:

if gloria has "carry over" minutes, (that is, any minutes paid for but not used in a month can be applied to her payment for minutes in the next month,) her total usage for the three months is: total minutes = 320 + 243 + 489 = 1052 minutes number of 200 minute blocks = 1052/200 = 5 r52 (that is 5 with a remainder of 52) rounding up the number of 200 minute blocks gives her usage for the three months as 6 blocks. the cost for six blocks is 6 x $25 = $150 she also has 200 - 52 or 148 carry over minutes if gloria pays each month and unused minutes are lost, applying the rounding up procedure to each month gives: first month usage of 320 minutes rounds up to 2 blocks of 200 minutes for a payment of 2 x $25 = $50 second month usage of 243 minutes rounds up to 2 blocks of 200 minutes for a payment of 2 x $25 = $50 third month usage of 489 minutes rounds up to 3 blocks of 200 minutes for a payment of 3 x $25 = $75 total payments for the three months are $50 + $50 + $75 = $175 get the plan with carry over minutes!