1. **State the problem:** Find $\frac{dy}{dx}$ when $y = (x^2 - 2x)^{\tan x}$ for $x > \sqrt{2}$.
2. **Use logarithmic differentiation:** Take natural logarithm on both sides:
$$\ln y = \ln \left((x^2 - 2x)^{\tan x}\right)$$
3. Apply log power rule:
$$\ln y = \tan x \cdot \ln (x^2 - 2x)$$
4. Differentiate both sides with respect to $x$:
$$\frac{1}{y} \frac{dy}{dx} = \frac{d}{dx} \left(\tan x \cdot \ln (x^2 - 2x)\right)$$
5. Use product rule on right side:
$$\frac{d}{dx} (u v) = u' v + u v'$$ where $u = \tan x$, $v = \ln (x^2 - 2x)$.
6. Compute derivatives:
$$u' = \sec^2 x$$
$$v' = \frac{1}{x^2 - 2x} \cdot (2x - 2) = \frac{2(x - 1)}{x^2 - 2x}$$
7. Substitute back:
$$\frac{1}{y} \frac{dy}{dx} = \sec^2 x \cdot \ln (x^2 - 2x) + \tan x \cdot \frac{2(x - 1)}{x^2 - 2x}$$
8. Multiply both sides by $y$:
$$\frac{dy}{dx} = y \left(\sec^2 x \cdot \ln (x^2 - 2x) + \tan x \cdot \frac{2(x - 1)}{x^2 - 2x}\right)$$
9. Recall $y = (x^2 - 2x)^{\tan x}$, so final answer is:
$$\boxed{\frac{dy}{dx} = (x^2 - 2x)^{\tan x} \left(\sec^2 x \cdot \ln (x^2 - 2x) + \tan x \cdot \frac{2(x - 1)}{x^2 - 2x}\right)}$$
Logarithmic Differentiation 6C3D04
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