Domain and Range

This week in math 10, I learned how to identify a coordinate plain’s Domain and Range.

The horizontal line, also known as the x-axis, is used to find the domain, and the vertical line, also known as the y-axis, is used to find the range.

To understand how to find Domain and Range, I will simplify it to only one line. Know to explain the next few examples.

Example #1

To describe this line, you list out the places where the dots are: {2,3,4,5}. You can not answer the question like this: {2-5} because that would imply decimals.

Example #2

The that arrow means that all numbers smaller than -6 are possible solutions for the equation and the unshaded circle means that -6 is not a possible solution. The answer would be written like this: {-6˃x}

Example #3

The fact that there are 2 circles means that all the possible solutions have to bee in between those 2 numbers. The shaded circle means that that the number circled is a possible answer. The answer would be written like this: {-1≤x˂7}

Know to introduce Range in.

Example #4

Starting with the Domain. The answer would be any real number because there is no base point and the arrows go both ways. For the range, the answer would be 8 because the height dose not vary.

D {xR}

R {8}