1:58:44
**UNIT 4**

Vector Differentiation: Introduction to Vector Differentiation, Gradient, Directional derivative, Problems on Gradient and Directional Derivative - Part 1, Problems on Gradient and Directional Derivative - Part 2, Divergence, Curl, Problems on Gradient,Divergence and Curl, Problems on Gradient,Divergence and Curl Part 1, Incompressible flow, Solenoidal and irrotational vector fields, Second order Operators, Del applied twice to point function, Del applied twice to point function Problems, Del applied twice to point function Problems Part 1, Del applied to products of point functions, Problems on Del applied to products of point functions, Problems on Del applied to products of point functions Part 1, �Laplacian operator, Vector identities