After completing the course the student will be able to work with more-variable real functions. He will be able to find extremes of such functions. In addition, the student will be able to calculate the derivative of functionals and also seek their extremes.
H. Anton, I. Bivens, S. Davis: Calculus, 2009
L.E. Elsgolc: Calculus of Variations, 2007
L. Gillman, R. H. McDowell: Calculus, New York, W.W. Norton & Comp. Inc. 1973.