Class 11 Maths Chapter 11 Introduction to Three Dimensional Geometry – Revision Notes

Quick revision notes for Class 11 Maths Chapter 11 (Introduction to Three Dimensional Geometry). These Class 11 Maths Chapter 11 notes are ideal for quick revision just before exams.

3D Coordinate System

• 3 mutually perpendicular axes (x,y,z); origin (0,0,0).
• 8 octants (vs 4 quadrants in 2D).
• Point = ordered triple (x,y,z).

Distance Formula

• d = √[(x2−x1)²+(y2−y1)²+(z2−z1)²].

Section Formula

• Ratio m:n: [(mx2+nx1)/(m+n), (my2+ny1)/(m+n), (mz2+nz1)/(m+n)].

One-Line Summary

3D coordinate geometry extends 2D concepts with a third (z) axis, dividing space into 8 octants, using natural extensions of the distance and section formulas.

Written by Satish

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