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X*3 - 2x*2 y*2 + 5x + y - 5 = 0Then dy/dx at x = 1, y = 1 is equal to..?​

Answer»

Given :

Function \bf\:x{}^{3}-2x{}^{2}\times\:y{}^{2}+5x+y-5=0

To Find :

\dfrac{dy}{dx} at x=1 and y=1

Formula's:

1) \: \frac{d(x {}^{n} )}{dx}  = nx {}^{n - 1}

2) \frac{d(constant)}{dx}  = 0

Solution :

\bf\:x{}^{3}-2x{}^{2}\times\:y{}^{2}+5x+y-5=0

DIFFERENTIATE with respect to x

3x {}^{2}  - (2x {}^{2}  \times 2y \frac{dy}{dx} + y {}^{2}  \times 4x) + 5 +  \frac{dy}{dx}  = 0

3x {}^{2}  - 4x {}^{2} y \frac{dy}{dx}   - 4x y {}^{2}  + 5 +  \frac{dy}{dx}  = 0

3x {}^{2}  - 4xy {}^{2}  + 5 =  \frac{dy}{dx} (4x {}^{2} y) -  \frac{dy}{dx}

3x {}^{2}  - 4xy {}^{2}  + 5 =  \frac{dy}{dx}(4xy {}^{2}  - 1)

\implies \dfrac{dy}{dx}  =  \dfrac{3x {}^{2} - 4xy {}^{2} + 5  }{4x {}^{2} y - 1}

\implies \dfrac{dy}{dx} at (1,1) =  \frac{3 - 4 + 5}{4 - 1}

\implies \bf \dfrac{dy}{dx} at (1,1)=  \dfrac{4}{3}

which is the required solution!

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More About Differention:

CHAIN rule

Let y=f(t) ,t = g(u) and u =m(x) ,then

\dfrac{dy}{dx}  =  \dfrac{dy}{dt}  \times  \dfrac{dt}{du}  \times  \dfrac{du}{dx}



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