In: Advanced Math
Let f left parenthesis x comma y right parenthesis equals cos left parenthesis pi space x right parenthesis plus 3 y squared minus 6 y. Which of the following are TRUE? Select ALL that apply. a. f has a saddle point at left parenthesis k comma 1 right parenthesis whenever k is an odd integer b. f has a saddle point at left parenthesis k comma 1 right parenthesis whenever k is an even integer c. f has a local minimum at left parenthesis k comma 1 right parenthesis whenever k is an odd integer d. f has a local maximum at left parenthesis k comma 1 right parenthesis whenever k is an even integer