SOLUTION: Is there a relationship between the sign (positive or negative) of the slope of a line and the angle the line makes with the x-axis? For example,if you graph y = 3x+5,versus the g

Algebra ->  Graphs -> SOLUTION: Is there a relationship between the sign (positive or negative) of the slope of a line and the angle the line makes with the x-axis? For example,if you graph y = 3x+5,versus the g      Log On


   

Question 775434: Is there a relationship between the sign (positive or negative) of the slope of a line and the angle the line makes with the x-axis?
For example,if you graph y = 3x+5,versus the graph of y = -3x+5
Answer by MathLover1(20850) About Me  (Show Source):
You can put this solution on YOUR website!
Yes! Most definitely.
The angle the line makes with x-axis is given by arctan or tan^-1 of the slope.
For example if the slope is 1 then the angle to the x-axis is arctan+%281%29+=+45 degrees
Size of the angle formed with the x-axis is related to the sign of the slope.
Lines with positive+slopes slant to the right, thus a smaller angle is formed with the x-axis.
Lines with negative slopes slant to the left, thus a larger angle is formed with the x-axis.

y+=+3x%2B5 (Green Line)
y+=+-3x%2B5 (Blue Line)