Vectors and 3D Geometry

5 solved problems from JEE previous year papers.

Vector Algebra

Vector d Perpendicular to Both a and b, With c·d=15

Given a=i+4j+2k, b=3i−2j+7k, c=2i−j+4k, find vector d perpendicular to both a and b with c·d=15, using the cross product a×b.
Three Dimensional Geometry

Direction Cosines of the Line 5x−3=15y+7=3−10z

Find the direction cosines of 5x−3=15y+7=3−10z and a point through which it passes, by converting to symmetric form with…
Vector Algebra

If 3a+2b=5c and 8a−7b=4c, Are a,b,c Collinear and Is |a|>|b|?

Given 3a+2b=5c and 8a−7b=4c, determine whether |a|>|b| and whether a, b, c are collinear vectors, by eliminating c between the…
Vector Algebra

Four Coplanar Points With Position Vectors a,b,c,d, Which Identity Holds

If four distinct points with position vectors a,b,c,d are coplanar, which scalar triple product identity must hold? A worked…
Vector Algebra

Find Vector d Perpendicular to Both b and c, With d·a = 21

Given vectors a=4i+5j−k, b=i−4j+5k, c=3i+j−k, find vector d perpendicular to both b and c such that d·a=21, by solving a system…