To understand this picture 2 cones that are stacked one on top of another. A double-napped cone is created when a generator is rotated about a fixed vertical axis. A line is created when the cone is cut by a plane containing the generator. Please see the attachment to help you understand this.
I hope this helps, Regards.
Answer:
Step-by-step explanation:
(a) You are given two points, (d, C) = (360, 342) and (780, 426). The two-point form of the equation for a line can be helpful.
... y = (y2 -y1)/(x2 -x1)(x -x1) +y1
Using the given points and variables, ...
... C = (426 -342)/(780 -360)(d -360) +342
... C = (84/420)(d -360) +342
... C = 0.20d +270 . . . . the equation for cost as a function of miles driven
(b) Fill in the value for d and do the arithmetic.
... C = 0.20·1800 +270 = 360 +270 = 630
(c) The slope of the curve is (change in dollars)/(change in miles) = $/mile, the cost of each mile driven. (It is $0.20 per mile.)
(d) The C-intercept is C(0) = cost for 0 miles driven. (It is $270.)
(e) Both your own experience and the problem statement tell you that the cost of vehicle operation varies with miles driven. If nothing else, you need to pay more for gas the farther you drive.
(In real life, you don't expect the model to be exactly linear, becasue you get a large jump in cost when you reach certain maintenance interval miles: 15,000, 30,000, and so on.)
