1) consider the function: f(x,y) = y^2 + 6y -x +8

A ) If k = 0 , the corresponding level curve is a vertex parabola ( 1,3 ) .

B ) If k = 0 , the corresponding level curve is a vertex parabola ( -1 , -3 ) . C) If k = 0 , the corresponding level curve is a vertex parabola ( -1,3 ) . D) If k = 0 , the corresponding level curve is a parabola with vertex ( 1 , -3 )

2) Determine the domain of the function f (x,y,z) defined by:

\fA Dominio= {(x, y, z) ER' , x' ty' + 2 >0,y>0,=>0} B Dominio= {(x, y, z) ER', x? ty? + 2? >4 A x 20,y2 0,2 20} C Dominio= {(x, y, z) ( R3, x? ty? - 2?