Implicit Fundamental Involution
1. The problem states that for a differentiable function $y(x)$, the equation $x + y^4 = 10$ holds with $y \neq 0$. We want to find $\frac{dy}{dx}$.
2. Differentiate both sides implicitly with respect to $x$. The derivative of $x$ is 1, and using the chain rule, the derivative of $y^4$ is $4y^3 \frac{dy}{dx}$. So we get:
$$1 + 4y^3 \frac{dy}{dx} = 0$$
3. Solve for $\frac{dy}{dx}$:
$$4y^3 \frac{dy}{dx} = -1$$
$$\frac{dy}{dx} = \frac{-1}{4y^3}$$
4. Hence, the correct answer is (C) $\frac{dy}{dx} = -\frac{x}{4y^3}$? Wait, options do not perfectly match; check again.
Actually, from the original equation $x + y^4 = 10$, so $x = 10 - y^4$. When differentiating, treat $y$ as a function of $x$.
Implicit differentiation:
$$\frac{d}{dx}(x) + \frac{d}{dx}(y^4) = \frac{d}{dx}(10)$$
$$1 + 4y^3 \frac{dy}{dx} = 0$$
$$4y^3 \frac{dy}{dx} = -1$$
$$\frac{dy}{dx} = -\frac{1}{4y^3}$$
Since $x + y^4 = 10$ is given, the derivative does not depend on $x$, so answer (C) $-\frac{x}{4y^3}$ is incorrect. The exact derivative is $-\frac{1}{4y^3}$.
Thus answer (A) is $\frac{1}{4y^3}$ (positive), so no.
Answer (B) is $\frac{1}{y^4}$ no.
Answer (C) $-\frac{x}{4y^3}$ no.
Answer (D) $\frac{9}{4y^3}$ no.
Answer (E) $\frac{10 - x}{y^4}$ no.
The closest is (none) but derivative is $-\frac{1}{4y^3}$.
We'll choose derivative as $-\frac{1}{4y^3}$ and note that the correct choice is not given but the calculation is as above.
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5. We have $h(x) = \int_0^{x^2} g(t) dt$ and want $h'(x)$.
Apply the Fundamental Theorem of Calculus and chain rule:
$$h'(x) = g(x^2) \cdot \frac{d}{dx}(x^2) = g(x^2) \cdot 2x = 2x g(x^2)$$
Hence the correct answer is (C).
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6. Given $f(f(x)) = x$ for all $x$ in the domain, $f$ is an involution, and therefore its graph is symmetric about the line $y=x$.
Graphically, such a function is typically strictly increasing and passes through the origin with symmetry about $y=x$.
Check options:
(A) strictly increasing curved function with origin pass and range from near 0 to 2 for x from negative to positive. This could be an involution.
(B) strictly decreasing - fails symmetry for involution
(C) cubic-like with local min at origin - not typical for involution
(D) curve with asymptotes - unlikely
(E) strictly decreasing past origin - no
Hence (A) is the plausible graph for $f$.
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Final answers:
- Q4 derivative: $\boxed{\frac{dy}{dx} = -\frac{1}{4y^3}}$ (no matching option)
- Q5 derivative: $\boxed{h'(x) = 2x g(x^2)}$
- Q6 graph: (A)