CPM Homework Help : INT2 Problem 3-106

Write the equation of the line that has a slope angle of $25^\circ$ and a $y$ -intercept of $(0,4)$ . Sketch a graph of this line. Assume the slope of the line is positive. .

Step 1:

$\text{tan (slope angle) }= \left(\frac{\text{opposite side}}{\text{adjacent side}}\right) =\frac{\Delta y}{\Delta x} = \text{slope}$

Since the $\tan(25^\circ)\approx0.466$ then the $\text{slope} ≈ 0.466$

Step 2:

Substitute the slope ( $m$ ) and the $y$ -intercept ( $b$ ) in the $y = mx + b$ form for a line.

More Help:

Note: When a $y$ -intercept is given as a point, the $y$ -intercept in an equation is the $y$ -coordinate only!

Use the eTool below to graph the line.
Click the link at right for the full version of the eTool: Int2 3-106 HW eTool