This week in Math 10 I learned domain and range through the catch up lesson with Ms. Burton. Domain and range are used when reading graphs to calculate how high, low, left and right the points on the graph are.
Domain is used when calculating along the x-axis, so the left-most and right-most points. For example in the first graph, to write the domain properly you have to take into account what is on the end of the point because it could be an arrow, and white circle or a black circle. In this case we have one arrow (which means infinity) and one black circle (which means included). We write the coordinates in order from left to right so the coordinates for domain for this example would be negative infinity and 5.
Range is used when calculating along the y-axis, so the highest and lowest points. For example in the second graph we have two open dots`so we know that we will have exact points. We calculate range the same way we calculate domain and can write the coordinates from left to right and we get 4 and -4 by going along the y-axis. That’s how to simply find out a graphs domain and range.
