Finding the extremum of function z = XY (a-x-y) I'm going over the exam,

First, Z '(x) = x * (a-x-2 * y) = 0
z'(y)=y(a-y-2*x)=0
Four groups of solutions (0,0) (a, 0) (0, a) (A / 3, a / 3) are obtained
1. (0,0), f '', XX = 0, f '', xy = a, f '', YY = 0, AC-B ^ 2

RELATED INFORMATIONS

1. Finding the conditional extremum of the function z = XY satisfying the condition x + y = 1
2. Finding the extremum of function z = x ^ + XY + y ^ + X-Y + 1
3. Find the extremum of function z = XY (3-x-y), (x > 0, Y > 0)
4. Find the conditional extremum of function z = XY under given condition x + y = 2
5. Find the extremum and maximum value of function y = x ^ 3-x ^ 2-x + 1 in X belonging to [- 2,2]
6. Find the extremum of function f (x, y) = x × x × X-Y × y × y + 3 × x × x + 3 × y × y-9x
7. Find the monotone interval and extremum of the following function, y = (x-1) (x + 1) ^ 3, y = 2 / 1 + x ^ 2
8. The number of extreme points of function y = x ^ 4 / 4-x ^ 3 / 3 is
9. Find the extreme value of the following function y = x ^ 4-8 * x ^ 3 + 18 * x ^ 2-1
10. What is the extremum of the function z = x ^ 2-y ^ 2 + 1? A.(0,0) B.(0,1) C.(1,0)
11. The monotone interval of function y = radical X-1 + radical x + 3 is The monotone interval of function y = radical (x-1) + radical (x + 3) is
12. Finding monotone interval of y = root sign x + X + 1
13. Find the monotone interval y = under the root sign (- x ^ 2 + 2x + 3)
14. Y = 2x square - 4x + 3 / x square + 2x + 3 to find the range of this equation?
15. Find the range of y = - 2 divided by x square + 2x-1
16. Y = (4x square + 2x + 5) / (2x + 1) (x is greater than or equal to 1)
17. Find the range of function y = 2x2 + 4x − 7X2 + 2x + 3
18. Find the range of y = (2x ^ 2 = 4x-7) \ (x ^ 2 + 2x + 3)
19. The range of function y = x √ (1-2x) is Sorry, the title is wrong, y = x √ (1-2x ^ 2)
20. The range of function y = 2x ^ + 1 is? The sign after X is square!