Lines And Slopes Worksheets With Answers - Hec Montreal (Page 2 of 9) in pdf

Lines And Slopes Worksheets With Answers - Hec Montreal Page 2

Example

represents a straight line whose slope is 3

The equation

and whose ‐intercept is ‐4

4 .

Note that the and variables are arbitrary. They could have just as easily been

named and , as it is the case in supply and demand curve. It is important to

determine which of these variables constitutes the independent variable (which

we place on the horizontal axis) and which constitutes the dependent

variable(which we place on the vertical axis).

2. How to obtain a straight line equation

We will often need to find the equation of a straight line, given certain

information. For example, what is the equation of the line passing points (1,4)

and 2,8 ? In order to answer this question, one needs to find the values of

and that describe the straight line.

1. Determine the slope

By definition, the slope is measured by the relation

∆

The slope of the line passing by (1,4) and (2,8) would be

∆

which indicates that for a move of one unit to the right, there is a move of 4 units

upwards. Also note that the choice of the "first" and the "second" point will not

affect the calculation of the slope:

∆

2. Find the –intercept

In order to find the value of , one must use a known point of the line and the

slope we just determined:

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