Vit.e., grad t is normal to the surtace f(x, y, z) = c. vect theorem lf n be a unit vector normal to the level surface f(x, y, z) = c at a point p in th directi

EXPLAIN THE STATEMENT OF THIS THEOREM. VIT.e., grad t iS normal to the surtace f(X, y, Z) = C. vect Theorem lf n be a unit vector normal to the level surface f(x, y, z) = c at a point P in th direction of f increasing andn be the distance of P from a fixed point A in the direction of n, then. df grad f= dn Proof Rv thac