2. Use a double integral to find the volume in the first octant bounded by f(x,y) =1- xy.x = y, and x = y. 5 a. b. C. 12 d. 12 e. None of these 83. Find the average value of f(x, y) = y over the rectangle with vertices (0, 0), (2, 0), (2, 3), and (0, 3). b. WIN C. d. N | 0 a. e. None of these5. Find the surface area of that portion of the paraboloid z = 1- x - y that lies above the xy-plane. *(515 - 1 ) a. b. 2 C. d. 6 e. None of these 67. The gradient of f(x,y) = 3x - 2y*2 + 5 at (6,1) is: a. 6i - 4j + 10k b. 3i - 4j + 5k c. 3i - 4j d.6i + 4j e. not given 8. Evaluate (12y/x)dy from y = 5x to y = x^5. a. 12(x^9 - 25x) b, 6x(x^8 - 25) c. 6(x^9 - 5x) d. 6(25x -x^9) e. not given 9. Find the value of (5x + y)dydx for y & [0,2] and x & [-2,2]. a. 13 b. 9 C. 6 d. 8 e. not given 10. Determine Jr*2sinOrdrd0 for [ 0 s r s (1+tcos0)] and 0 s 0s n. a. 1.6 b. 6.4 C. 0 d. x e. not given