9.當存在其值為一3。請問下列哪個選項是正確的? (A)a=0(B)a?=9(C)a=-3(D)a=3(E)以上皆非。

13. A region A is bounded by the hyperbolas (雙曲線) xy = 1 and xy = 2, and the curves xy2 = 3 and xy2 = 4. The area of A is denoted by area.. Use the change of variables u = ry and u = ay', the area of the image of the region A in the coordinate space determined by (u,v) under the transformation is called areat. 請問下列哪些選項是正確的? (A) areao =In4-1n3(B)(C) (D) The Jacobian determinant (E)