How to find the slope of a line given two points

Slope of a line

  • A line is the set of points forming a straight path on a plane.

  • The slope of the line through the distinct points  P_1 (x_1,y_1) first term and  P_2(x_2,y_2) is:

    m=\displaystyle{\frac{y_2-y_1}{x_2-x_1}}

  • 1.  Find the slope between (-3, 2) and (3, 7).

    2.  Find the slope between (-3, 6) and (5, 2).

    3.  Find the slope between (5, 4) and (5, 2).

    4.  Find the slope between (-3, 2) and (5, 2).

    • The slope of the line measures the “steepness of the line”.
    • The bigger the absolute value of the slope, the steeper the line is.
    • Positive slope means “rising” line
    • Negative slope means “falling” line
    • Undefined slope means vertical line.
    • Zero slope means horizontal line.
    1. Tell whether the slope of the following are positive, negative, zero or undefined.

    1. Red

    b.  Blue

    c.  Purple

    d.  Green

    2.  Determine the slope of the line given its graph

    a.

    b. 

    3.  Determine the slope of the line containing each given pair of points.

    1. (2,3) and (5, -1)

    b. (2,3) and (2, -1)

    c.  (4,-1) and (-2, -1)