25. the valuc ofthe surfacc integral (xa)-dš, where a = iy +ja+k and s is the surface defined by the paraboloid z=l- r-y, with z20 isgiven by (a) el.c.u. 20171

25. The valuc ofthe surfacc integral (xA)-dš, where A = iy +ja+k and S is the surface defined by the paraboloid z=l- r-y, with z20 isgiven by (a) EL.C.U. 20171 (6)1 (c) 1 (d) - -Tt