Question

The function y= 3.5x + 2.8 represents the cost y (in dollars) of taxi ride of x miles.a) identify independent and dependent variables.b) you have enough money to travel at most 20 miles in the taxi. Find the domain and range of the function.

Answer 1

a) To identify the dependent variable and the independent variable, we must first look at which variable varies with respect to another, so the dependent variable will be the one that goes with respect to another, thus, the independent variable, in this case, is x, and the dependent variable is y because it depends on the value of x to know its value.

b) We know that the maximum value that y can take is 20, we also understand that the minimum value is 2.8 for x=0. Mathematically we write that the range is: [2.8,20].

To know the domain, we can clear x and replace y by 20:

`x=(y-2.8)/(3.5)=(20-2.8)/(3.5)=4.914`

So the domain is: [0,4.914]