Question

a) Which value is the dependent variable? Which is the independent variable? Explain.b) How would you represent t = 5 on the table? On the graph? Explain. c) Describe two ways to represent the total cost of skating for half an hour.d) Given any equation with two variables, explain how to draw a table and a graph.

Answer 1

a)

The cost C is the dependent variable because the cost depends on the time t.

Cost 'c' = dependent variable

Time 't' = Independent variable

b)

By substituting t = 5 in the equation c = 2.5t + 6

Time, t 2.5t + 6 Total cost (c)

5 2.5(5) + 6 18.5

c)

First, by substituting t = 1/2 in the total cost equation.

`\begin{gathered} \text{Total cost c = 2.5t + 6} \\ c\text{ = 2.5 }*(1)/(2)\text{ + 6} \\ \text{c = 1.25 + 6 } \\ \text{c = \$7.25} \end{gathered}`

Second, by drawing a line from the x-axis at t = 1/2 to intersect the graph and then trace the point to the y-axis.

d)

The equation is y = 3x + 5, where y and x are two variables.

To plot a table, choose a range of values of variable x and find the corresponding value of y.

Plot the graph using x as the horizontal axis and y as the vertical axis.