Various Forms Of The Equation Of A Line
Chapter Name : Straight Lines |
Sub Topic Code : 104_11_10_03_06 |
Topic Name : Various Forms Of The Equation Of A Line |
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Sub Topic Name : Normal Form |
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Introduction
A non-vertical line makes an angle with positive direction of x-axis and a perpendicular can be drawn to it from origin. We can determine the equations of such lines.
Pre-Requisites:
Idea about the coordinate plane, slope of a line, linear equation in two variables.
Real Life Question:
The perpendicular distance of the line from origin is 4 units and the normal to the line from origin makes an angle of 15° with positive x-axis. What is the equation of the line?
Key Words / FlashCards
| Key Words | Definitions (pref. in our own words) |
|---|---|
| Equation of a line in normal form. | The equation of a line having normal distance p from the origin and angle ? which the normal makes with positive direction of x-axis is given by: x cos??+ y sin??=p |
Learning aids / Gadgets
| Gadgets | How it can be used |
|---|---|
| Graph and Scale | Plot the line whose perpendicular distance from origin is 4 units and the normal to tithe line from origin makes an angle of 15° with positive x-axis. |
Real life uses :
Equations of lines are a compact form of defining a line if someone wants to convey over email or telephone. Equation of lines is employed to find the locus of the trajectory of a moving body.
Practical examples around us
| Examples | Explainations |
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What you learn in Theory:
What is the normal to a line, perpendicular distance from origin, equation of line in normal form?
What you learn in Practice:
How to find the equation of line in normal form?