Use this information to answer questions Q9 to Q12. Given that tu=uv+x22u,tv=u+v+x22v,u=rcos and v=rsin 9. Find tu, in terms of ,r and t A. rsintcostr B. rsint+costr C. rsint+costr D. rsint+costr 10. Find x22v A. rsinx22+cosx22r B. cosx22+sinx22r C. rcosx22+sinx22r D. cosx22r+r2sinx22 11. tr is the same as ... A. r+x22r B. r+x22r C. r++x22+x22r D. r+x22r 12. Which of the following expression is equal to x22 A. rt B. +t C. +tr+rt D. +r1t 13. Which of the following vector field is conservative? A. x2yi+(3xyz)j+z3k B. x2+y2yi+x2+y2xj+0k C. xyi+zj+z2xk D. (x3y)i+y5j+ezk 14. Which of the following statement is true? A. The Stokes' theorem is a vector form of the Green's theorem B. The divergence theorem is an extension of stokes' theorem C. The Green's theorem relates the flow of fluid that surrounds a point and the fluid flow inside the point. D. The curl of a fluid flow is a vector form of divergence of same fluid flow