Question: What is the angle between the lines y = 3x + 2 and y = -1/3x + 1? (2021)
Options:
Correct Answer: 90 degrees
Exam Year: 2021
Solution:
The slopes are m1 = 3 and m2 = -1/3. The angle θ = tan⁻¹(|(m1 - m2) / (1 + m1*m2)|) = tan⁻¹(10/8) = 90 degrees.