यदि $u = e^{-x^2 - y^2}$ है,तो

यदि $u = \log (x^3 + y^3 + z^3 - 3xyz)$ है,तो $\left( \frac{\partial u}{\partial x} + \frac{\partial u}{\partial y} + \frac{\partial u}{\partial z} \right) (x + y + z) =$

यदि $u = \log_e(x^2 + y^2) + \tan^{-1}\left(\frac{y}{x}\right)$ है,तो $\frac{\partial^2 u}{\partial x^2} + \frac{\partial^2 u}{\partial y^2} = $

यदि $u = \sin^{-1} \sqrt{\frac{x^2 + y^2}{x + y}}$ है,तो $x u_x + y u_y$ का मान ज्ञात कीजिए।

यदि $f(x, y) = \frac{\cos(x - 4y)}{\cos(x + 4y)}$ है,तो $\left. \frac{\partial f}{\partial x} \right|_{y = \frac{x}{4}}$ का मान ज्ञात कीजिए:

यदि $f(x, y) = \frac{\cos(x - 4y)}{\cos(x + 4y)}$ है,तो $\left. \frac{\partial f}{\partial x} \right|_{y = \frac{x}{2}}$ का मान क्या होगा?