d/(dx)(x^3+y^3=4xy+1)--(1)ddx(x3+y3=4xy+1)−−(1)
we will differentiate wrt" "xwrt x. Remembering that when differentiating yy we multiply by (dy)/(dx)dydx by virtue of the chain rule. Also on the RHS RHS we will need the product rule on the first term
(1)rarr3x^2+3y^2(dy)/(dx)=4y+4x(dy)/(dx)+0(1)→3x2+3y2dydx=4y+4xdydx+0
rearrange for (dy)/(dx)dydx
3y^2(dy)/(dx)-4x(dy)/(dx)=4y-3x^23y2dydx−4xdydx=4y−3x2
(dy)/(dx)(3y^2-4x)=4y-3x^2dydx(3y2−4x)=4y−3x2
=>(dy)/(dx)=(4y-3x^2)/(3y^2-4x)⇒dydx=4y−3x23y2−4x
:.[(dy)/(dx)]_(color(white)(=)(2,1))=(4xx1-3xx2^2)/(3xx1^2-4xx2
=(4-12)/(3-8)=-8/-5=8/5