## Precalculus (6th Edition) Blitzer

slope = $\dfrac{1}{3}$ The line through the two given points rise.
RECALL: (1) The slope $m$ of a line that passes through the points $(x_1, y_1)$ and $(x_2, y_2)$ can be found using the formula: $m=\dfrac{y_2-y_1}{x_2-x_1}$ (2) A line with a positive slope rises from left to right. A line with a negative slope falls from left to right. (3) A line with a slope of 0 is horizontal. A line with an undefined slope is vertical. Solve for the slope of the line using the formula in (1) above to obtain: $m=\dfrac{4-3}{2-(-1)}=\dfrac{1}{2+1}=\dfrac{1}{3}$ The slope is positive therefore the line through the given points rises.