below A person s height depends on their age This situation describes a function where the two variables are the person s age in years and the person s height in inches Which variable is age and which variable is height and What would you expect the range of the function to be if Where would you expect the function to be increasing and decreasing The function should be increasing from about x to about x The function should be decreasing from about x to about x Which of the images below could be a graph of f x f x Graph starts at a 0 increases to 70 inches at 18 yrs stays the same until declining slightly before age 85 g x A straight line graph starting at zero that increases equally over time until it reaches 70 inches at 85 years h x Hyperbola starts at 0 increases to 70 in at 40 yrs declines until it returns to original height at 85 What would the y intercept of the function tell you in terms of age and height Would you expect such a point to exist The y intercept tells us I expect such a point to exist because What would the x intercept of the function tell you in terms of age and height Would you expect such a point to exist The x intercept tells us I expect such a point to exist because For more information on this topic look in section 1 2 of your textbook especially at Example 7 You might also look at the Functions Domain and Range presentation