MCQ
If $u = {e^{ - {x^2} - {y^2}}}$, then
  • A
    $x{u_x} = y{y_y}$
  • $y{u_x} = x{u_y}$
  • C
    $y{u_x} + x{u_y} = 0$
  • D
    ${x^2}{u_y} + {y^2}{u_x} = 0$

Answer

Correct option: B.
$y{u_x} = x{u_y}$
b
(b) ${u_x} = {e^{ - {x^2} - {y^2}}}( - 2x) = - 2ux$, 

${u_y} = {e^{ - {x^2} - {y^2}}}( - 2y) = - 2uy$

$y{u_x} = x{u_y}$.

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Similar questions

If four vertices of a regular octagon are chosen at random, then the probability that the quadrilateral formed by them is a rectangle is
In a box containing $100$ eggs, $10$ eggs are rotten. The probability that out of a sample of $5$ eggs none is rotten if the sampling is with replacement is
All possible values of $\theta \in[0,2 \pi]$ for which $\sin 2 \theta+\tan 2 \theta>0$ lie in
Straight lines $2x + y = 5$ and $x - 2y = 3$ intersect at the point $A$ . Points $B$ and $C$ are chosen on these two lines such that $AB = AC$ . Then the equation of a line $BC $ passing through the point $(2, 3)$ is
Consider a pair of circles $(|x| -1)^2 + y^2$ = $1$ , Ram is moving away from origin along one circle in clockwise direction at the rate $2\ m/s$ and Shyam is moving away from origin along other circle in anticlockwise direction at the rate $1\ m/s$ . If Ram and Shyam start their journey from origin, then rate of change of distance between Ram and Shyam at the instant when Ram crosses $x-$ axis first time, is
Let $A =\left[ a _{ ij }\right]$ be a $3 \times 3$ matrix such that $A \left[\begin{array}{l}0 \\ 1 \\ 0\end{array}\right]=\left[\begin{array}{l}0 \\ 0 \\ 1\end{array}\right], A \left[\begin{array}{l}4 \\ 1 \\ 3\end{array}\right]=\left[\begin{array}{l}0 \\ 1 \\ 0\end{array}\right]$ and $A \left[\begin{array}{l}2 \\ 1 \\ 2\end{array}\right]=\left[\begin{array}{l}1 \\ 0 \\ 0\end{array}\right]$, then $a _{23}$ equals:
If $f (x) =$ $\frac{{\ell \,n\,\,\left( {{e^{{x^2}}}\,\, + \,\,2\,\sqrt x } \right)}}{{\sqrt x }}$ is continuous at $x = 0$ , then $f (0)$ must be equal to :
The void relation on a set $A$ is
If $\sin \alpha = \frac{{ - 3}}{5},$ where $\pi < \alpha < \frac{{3\pi }}{2},$ then $\cos \frac{1}{2}\alpha = $
Let $A, B, C$ be three points in xy-plane, whose position vector are given by $\sqrt{3} \hat{i}+\hat{j}, \hat{i}+\sqrt{3} \hat{j}$ and $a \hat{i}+(1-a) \hat{j}$ respectively with respect to the origin O . If the distance of the point C from the line bisecting the angle between the vectors $\overrightarrow{\mathrm{OA}}$ and $\overrightarrow{\mathrm{OB}}$ is $\frac{9}{\sqrt{2}}$, then the sum of all the possible values of a is :