Problem (3) Find the relative extrema of the function f(x, y) = x3 - 12xy + 8y3, (x,y)

Instruction: This is a closed book exam. There are 10 problems and each is worth 10 points. Write everything CLEARLY, any ill-explanation or bad handwriting on your answer sheet should cause no credits. It is YOUR responsibility to turn in a clean, well-organized answer sheet. Problem (1) Find exp(az) cos (bx)dn.