Subject: Precalculus: Angle of Intersection of Two Lines
Name: Veronica Patterson
Question:
Thanks.
Hi again Veronica Since you say "I used the difference identity of tangent to figure out the answer." I assume you know that the slope of a line is the tangent of the angle, measured counterclockwise, between the Xaxis and the line. I drew a diagram of the two lines and marked in red the angles theta_{1} anf theta_{2}. The tangents of theta_{1} and theta give the slopes of the two lines. I then drew a horizontal line (in blue) through the intersection of the two lines and marked the angles again, this time in green. It should be clear now that the angle between the two lines is theta_{1}theta_{2}. The slopes of the two lines are 3 and 1/2 so you can use the result from the previous problem to calculate tan(theta_{1}theta_{2}). Once you know the value of tan(theta_{1}theta_{2}) you should be able to deduce theta_{1}theta_{2}. Cheers,Harley
