GATE2015-3-2

Question

The contour on the $x-y$ plane, where the partial derivative of $x^{2} + y^{2}$ with respect to $y$ is equal to the partial derivative of $6y+4x$ with respect to $x$, is

• A. $y=2$
• B. $x=2$
• C. $x+y=4$
• D. $x-y=0$