28 640 18 e. - 5. The critical point (a,b) of the two dimensional function f (x, y) can be found as from system of two equations: A - f. (a,b) -0 and " - f (a,b) = 0. The critical point of the two dimensional function f (x, y) = xy-y2 -2x3+7x 9. Use Chain rule to evaluate - for the following function. a. (1,2) b. (2, 1 ) c. (V2, 1 ) d. (4, 2) c. (-2 , -1) at z=x'ty' , x=Int , y=e' +5t a. 2xInt + 2y(5 +e') $ 2ini + (101 +2e )(5 +e') c . ( 2x + 2y ) ( = + e ) d. 2 Int-+ 10e' c. 2Int +10+2e' 6. Which one of the following series is convergent 10. Which of the following is the domain of the following function a . b. n! . W n+2 y-x -8 2" mon + 2 2n' +3n+4 f (x, y) = A e. None of them. 7. The result of the following iterated integral [ [ (y + 2 )ixdy is mlin d 8. Which one of the following is the result of the following iterated integral (2y + 1) dA where R is the region bounded by the curve y = x? and by the line y = 2x