pls help

Determine which of the following is true about f(x,y)=8x2+7y2+2. O f has a saddle point at (0,0,2). 0 f has a relative maximum at (0,0,2). 0 f has a relative minimum at (0,0,2). 0 f has no critical points. Determine which of the following is true about f(x,y) = -4x2 10y2 3. O f has a relative minimum at [00-3]. 0 f has no critical points. 0 f has a saddle point at (0,0,-3). 0 f has a relative maximum at (0,0,-3). The second partial derivatives of f (x, y) are required to determine the critical points of f. 0 True 0 False How many extrema does the function f (x, y) = 9 x2 7 have? (Hint: Notice that this is a function of two variables, but one of the variables does not affect the outcome. What does this mean about the graph? Can we sketch the graph when y = 0? When y = 5? Does the graph have extrema at these values of y? What about other y values?) 0 Innitely many extrema 0 Two extrema 0 One extrema O No extrema