`f(x,y)=x^3+y^3=2xy`
Find Implicit differentiation, Derivative with respect to xSolution:Method-1: using Chain Rule`x^3+y^3-2xy=0`
After implicit differentiation
`d/(dx)(x^3+y^3-2xy)=3x^2+3y^2y'-2y-2xy'`
`d/(dx)(x^3+y^3-2xy)`
`=d/(dx)(x^3)+d/(dx)(y^3)-d/(dx)(2xy)`
`d/(dx)(y^3)=3y^2y'`
`d/(dx)(y^3)`
`=3y^2*d/(dx)(y)`
`=3y^2*y'`
`=3y^2y'`
`d/(dx)(2xy)=2y+2xy'`
`d/(dx)(2xy)`
`=2*(d/(dx)(x))y+2x(d/(dx)(y))`
`=2*1y+2x(y')`
`=2y+2xy'`
`=3x^2+3y^2y'-(2y+2xy')`
`=3x^2+3y^2y'-2y-2xy'`
`3x^2+3y^2y'-2y-2xy'=0`
`=>3y^2y'-2xy'+3x^2-2y = 0`
`=>3y^2y'-2xy' = -3x^2+2y`
`=>y'(3y^2-2x) = -3x^2+2y`
`=>y' = (-3x^2+2y)/(3y^2-2x)`
`=>y' = ((-3x^2+2y)/(3y^2-2x))`
Method-2: using partial derivatives `Fx,Fy`. If `F(x,y)=0`, then `y'=-(Fx)/(Fy)``Fx=(del)/(del x)(x^3+y^3-2xy)=3x^2-2y`
Now,
`del/(delx)(x^3+y^3-2xy)`
`=del/(delx)(x^3)+del/(delx)(y^3)-del/(delx)(2xy)`
`del/(delx)(y^3)=0`
`del/(delx)(y^3)`
`=3y^2*del/(delx)(y)`
`=3y^2*0`
`=0`
`del/(delx)(2xy)=2y+0`
`del/(delx)(2xy)`
`=2*(del/(delx)(x))y+2x(del/(delx)(y))`
`=2*1y+2x*0`
`=2y+0`
`=3x^2+0-(2y+0)`
`=3x^2+0-2y-0`
`=3x^2-2y`
`:.(del)/(del x)(x^3+y^3-2xy)=3x^2-2y`
`Fy=(del)/(del y)(x^3+y^3-2xy)=3y^2-2x`
Now,
`del/(dely)(x^3+y^3-2xy)`
`=del/(dely)(x^3)+del/(dely)(y^3)-del/(dely)(2xy)`
`del/(dely)(x^3)=0`
`del/(dely)(x^3)`
`=3x^2*del/(dely)(x)`
`=3x^2*0`
`=0`
`del/(dely)(2xy)=0+2x`
`del/(dely)(2xy)`
`=2*(del/(dely)(x))y+2x(del/(dely)(y))`
`=2*0y+2x*1`
`=0+2x`
`=0+3y^2-(0+2x)`
`=0+3y^2-0-2x`
`=3y^2-2x`
`:.(del)/(del y)(x^3+y^3-2xy)=3y^2-2x`
`y'=-(Fx)/(Fy)`
`:.y'=-(3x^2-2y)/(3y^2-2x)`
`:.y'=(-(3x^2-2y))/(3y^2-2x)`
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