## Thomas' Calculus 13th Edition

$\nabla g(x,y,z)=-[\dfrac{2xi}{(x^2+y^2)}+ \dfrac{2yj}{(x^2+y^2)}]+e^z k$
Re-write as: $g(x,y,z)=e^{z}-\ln (x^2+y^2)$ Thus, the gradient field can be computed as $\nabla g(x,y,z)=e^{z}-\ln (x^2+y^2)=\dfrac{1}{2} [\dfrac{2x}{(x^2+y^2+z^2)}i +\dfrac{2y}{(x^2+y^2+z^2)} j +\dfrac{2z}{(x^2+y^2+z^2)} k ]$ or, $\nabla g(x,y,z)=-\dfrac{2xi}{(x^2+y^2)}+ [-\dfrac{2yj}{(x^2+y^2)}]+e^z k$ or, $\nabla g(x,y,z)=-[\dfrac{2xi}{(x^2+y^2)}+ \dfrac{2yj}{(x^2+y^2)}]+e^z k$