Question: What is the angle between the lines y = 2x + 3 and y = -1/2x + 1?
Options:
Correct Answer: 90 degrees
Solution:
The slopes are m1 = 2 and m2 = -1/2. The angle θ = tan^(-1) |(m1 - m2) / (1 + m1*m2)| = tan^(-1)(5/0) = 90 degrees.