# Equation of the line in normal form

Author:
Mathguru
Topic:
Equations
We can clearly see a line ‘a’ whose equation is lx + my = n. We also see p which is the length of the perpendicular on the line from the origin and α which is the angle made by this perpendicular with the positive x -axis. As we change the values of α and p using their corresponding slide bars, we can observe how the position of the line changes
Questions to think about: 1. Fix the value of α and change the value of p. What do we observe? 2. Fix the value of p and change the value of α. What do we observe? 3. Input values for $$cos\alpha$$, $$sin\alpha$$and p in the equation $x cos \alpha + y sin \alpha = p$and compare the result with the given equation of ‘a’ which is lx + my = n