Answers to Test #1 Review

1. arrow diagramèone arrow from each input value (output values do not matter)

table of valuesèrepeated input values must have same output value

set of ordered pairsèrepeated domain values must have same range value

graphèmust pass vertical line test (VLT: touch only one point on the graph)

2. Definitions are to help you understand the reading of questions.
3. a) 84 b) 16 c) 7 d) + 1
4. m = 9/14 y = (9/14)x – (123/14)
5. First graph (9, – 1) on the plane. Then use the slope 5 to get the next point by moving up 5 units and right 1 unit. Plot the second point and connect the two points.
6. x – intercept: (48,0) y – intercept: (0,18)
7. a) x = 3 b) y = 12
8. a) {1,3} b) Ø c) {(2,1),(2,3),(2,6),(4,1),(4,3),(4,6),(5,1),(5,3),(5,6)} d) (a,b)
9. a) D = {all reals} R = {all reals} b) D = { x >= -7} R = {y >= 0 }
10. Common questions like a) f(2) = ? Look on graph for x = 2, go to the curve, find the corresponding y-value. b) f(?) = 3 Look on graph at y=3 and find value(s) of x that produce it by looking for intersectons on the curve.
11. Examples: y = 2x + 8 Graph using the 3-second method. x = -2 Graph a vertical line at -2 on the x-axis. y = 5 Graph a horizontal line at 5 on the y-axis.
12. a) The set of points for the table would be (0, 59.9), (3, 68.5), (5, 67), (7, 83), and (9, 83.8).

b) The regression process considers ALL DATA POINTS, not just two or three of them.

c) The baseline year is 1973.

d) The slope for the line that passes through 1976 and 1982 is 2.55.

e) Coal production increases 2.81 tens of millions of short tons per year. The intercept of 58.95 means that in 1973 U.S. coal productionwas 58.95 tens of millions of short tons.

You will not be responsible for parts f and g on the first test.