Show there exists a differentiable function y=g(x) given an equation in x and y.

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Show that there exists a differentiable function $y = g(x)$ defined in some neighborhood $(a, b)$ of $0$ that solves the equation $(y^2 + 2)\times\sin y = 2\times x^3$. I.e., $$(g(x)^2 + 2)\times \sin g(x) = 2\times x^3$$ It is satisfied for all $x$ from the domain of $g$ and $g(0) = 0$.

Determine the derivative of this function at $0$?

I know that it relates to the implicit function theorem but I do not know how to do this.

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Hint:

Let $F$ be given by

$$F(x,y)=(y^2+2)\sin y-2x^3$$

By the implicit function theorem

$$g'(0)=-\frac{F_x(0,0)}{F_y(0,0)}$$

so long as $F_y(0,0)\neq 0$.


Alternatively, use the chain rule (and product rule) to differentiate both sides of

$$([g(x)]^2+2)\sin [g(x)]=2x^3$$

and then solve for $g'(x)$ and evaluate at $x=y=0$.