Question

if u= log {x^2+y^2/x+y} prove that x du/dx + y du/dy=1

Answer 1

let me try this again lol

Answer 2

i'm gonna try something easier

Answer 3

Okay

\[\large{\frac{du}{dx} \frac{1}{ \frac{y^2+x^2 }{x+y}}\frac{(2x + 2y\frac{dy}{dx})(x+y)+(1+\frac{dy}{dx}(x^2+y^2)}{(x+y)^2} }\]

Answer 4

why are you asking these dipti .....these are not tough ones ..these are ugly ones .

Answer 5

this is it i read it wrong at first
i think he means partial derivative
i used this same notation
i should had used correct notation but i used his

Answer 6

ok i did a typo there in numerator f(x)g'(x) - g(x)f'(x) not +

Answer 7

did you mean partial derivative?