How solve it? Derivate This Please!!!!

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1 Answer
Mar 17, 2017

(dF)/(dx)=(3(10x^3-7x^2)^2(60x^3-321x^2+140x))/(3x-10)^4

Explanation:

As F(x)=((10x^3-7x^2)/(3x-10))^3, let G(x)=(10x^3-7x^2)/(3x-10)

then we can use chain rule as F(x)=[G(x)]^3.

But before that let us workout (dG)/(dx)

using Quotient rule, which states if f(x)=(u(x))/(v(x))

then (df)/(dx)=((du)/(dx)xxv(x)-(dv)/(dx)xxu(x))/(v(x))^2

In G(x)=(10x^3-7x^2)/(3x-10), we have u(x)=10x^3-7x^2 and v(x)=3x-10.

and (du)/(dx)=30x^2-14x and (dv)/(dx)=3

Hence, (dG)/(dx)=((30x^2-14x)xx(3x-10)-3xx(10x^3-7x^2))/(3x-10)^2

= ((90x^3-300x^2-42x^2+140x)-(30x^3-21x^2))/(3x-10)^2

= (60x^3-321x^2+140x)/(3x-10)^2

Now (dF)/(dx)=3(G(x))^2xx(dG)/(dx)

= 3((10x^3-7x^2)/(3x-10))^2xx(60x^3-321x^2+140x)/(3x-10)^2

= (3(10x^3-7x^2)^2(60x^3-321x^2+140x))/(3x-10)^4