Trees grow faster and form wider rings in warm years and grow more slowly and form narrower rings in cooler years. The figure shows ring widths of a Siberian pine from 1500 to 2000.
(a) What is the range of the ring width function?
(b) What does the graph tend to say about the temperature of the earth? Does the graph reflect the volcanic eruptions of the mid-19th century?
when you're looking at a graph. If you want to determine if it's a function, you want to check to see if it passes the vertical line test. Remember, for a function. Every X value must have no more than one y value. So if you pass a vertical line through, you could only go through one point. So if I pass vertical line through lines through at various places here, notice I only go through one point. So yes, this is a function now. What's its domain and what's its range? So for the domain, we want to know what X values it goes through notice. It starts at an X value of negative two and goes over to an X value of two. So the domain in interval notation is negative. 222 That's equivalent to saying negative two is less than or equal to X is less than or equal to two. How about the range? So the range would be the Y values that it's going through. Notice that it's going through a Y value as low as negative one and as high as two and everything in between, so the range would be the interval from negative 1 to 2, and if you writing that as an inequality, it would be negative. One is less than or equal to why is less than or equal to two.