← CBSE Class 11
Straight Lines
Chapter Overview
The slope of a line joining (x1,y1) and (x2,y2) is m = (y2 - y1)/(x2 - x1). The chapter covers various forms: slope-intercept (y = mx + c), point-slope, two-point, intercept, and normal form. The general equation Ax + By + C = 0 represents all lines.
Angle between lines, parallel/perpendicular conditions, distance from a point to a line, and distance between parallel lines are covered.
Topics Covered
- Slope of a Line
- Slope-Intercept Form
- Point-Slope Form
- Two-Point Form
- Intercept Form
- Normal Form
- General Equation
- Angle Between Lines
- Parallel and Perpendicular Lines
- Distance Formulas
Key Formulas
m = (y2 - y1)/(x2 - x1)
y = mx + c
y - y1 = m(x - x1)
d = |Ax1 + By1 + C|/√A2 + B2
tan theta = |(m2 - m1)/(1 + m1m2)|
Real-World Applications
Applications: Computer graphics, architecture, navigation, road design, and economic modeling.
Study Tips
Tip: Convert between different forms fluently
Tip: Master the distance formula
Tip: Learn parallel vs perpendicular conditions