\( \lim _ { x \rightarrow + \infty } \frac { \operatorname { ouv } ( \frac { 1 } { x ^ { 2 } + 1 } ) \cdot n u x } { \sqrt { x ^ { 3 } + x ^ { 2 } + 5 } - x ^ { 2 } \sqrt { \frac { 1 } { x ^ { 2 } + 1 } } } \)

Determine whether or not the vector field \( (x-46 x y) i+\left(y^{2}-23 x^{2}\right) j \) is conservative. If it is, find a potential function. \( f(x, y)=\frac{x^{2}}{2}-23 x^{2} y+y^{3}+c \). The field is not conservative. \( f(x, y)=x^{2}-23 x^{2} y+\frac{y^{3}}{3}+c \). The field is not conservative. \( f(x, y)=\frac{x^{2}}{2}-x^{2} y+\frac{y^{3}}{3}+c \). The field is conservative. \( f(x, y)=\frac{x^{2}}{2}-23 x^{2} y+\frac{y^{3}}{3}+c \). The field is conservative. \( f \)

Label each expression as a scalar quantity, a vector quantity or undefined, if \( f \) is a scalar function and \( F \) is a vector field. \( \nabla \times(\nabla f) \) scalar vector

Compute the work done by the force field \( F \) along the curve \( C \). \( \mathrm{F}(x, y)=\langle 2 x, 2 y\rangle, C \) is the line segment from \( (1,1) \) to \( (5,4) \) \( W=\square \)

Evaluate the line integral. \( \int_{C} 5 z d s \), where \( C \) is the line segment from \( (5,0,1) \) to \( (6,-6,6) \) \( \int_{C} 5 z d s=\square \)

3.- \( \quad f(x)=x \ln \cos x \)