Send the following on WhatsApp
Continue to ChatSpherical gradient, divergence, curl and Laplacian https://peeterjoot.com/2016/11/09/spherical-gradient-divergence-curl-and-laplacian/
Spherical gradient, divergence, curl and Laplacian https://peeterjoot.com/2016/11/09/spherical-gradient-divergence-curl-and-laplacian/