Directional derivative: Better explained than in Serge Lang’s book

This is an attempt to explain directional derivatives better than how it is explained in Serge Lang’s seminal book “A Second Course in Calculus”. The directional derivative of is grad , where is a unit vector in the direction that we’re interested in. Let us suppose we need to find the derivative of function alongContinue reading “Directional derivative: Better explained than in Serge Lang’s book”