Math Problem Statement

If h(2) = 3 and h'(2) = −2, find d/dx (h(x))/x)|x=2

Solution

We are tasked with finding ddx(h(x)x)\frac{d}{dx} \left( \frac{h(x)}{x} \right) evaluated at x=2x = 2, given that:

h(2)=3andh(2)=2.h(2) = 3 \quad \text{and} \quad h'(2) = -2.

To approach this, we will use the quotient rule for differentiation. The quotient rule states that for two differentiable functions f(x)f(x) and g(x)g(x):

ddx(f(x)g(x))=g(x)f(x)f(x)g(x)(g(x))2.\frac{d}{dx} \left( \frac{f(x)}{g(x)} \right) = \frac{g(x) f'(x) - f(x) g'(x)}{(g(x))^2}.

In our case, f(x)=h(x)f(x) = h(x) and g(x)=xg(x) = x. Let's apply the quotient rule:

ddx(h(x)x)=xh(x)h(x)1x2.\frac{d}{dx} \left( \frac{h(x)}{x} \right) = \frac{x \cdot h'(x) - h(x) \cdot 1}{x^2}.

Now, evaluate this expression at x=2x = 2:

ddx(h(x)x)x=2=2h(2)h(2)122.\frac{d}{dx} \left( \frac{h(x)}{x} \right)\bigg|_{x = 2} = \frac{2 \cdot h'(2) - h(2) \cdot 1}{2^2}.

Substitute the known values h(2)=3h(2) = 3 and h(2)=2h'(2) = -2:

= \frac{-4 - 3}{4} = \frac{-7}{4}.$$ Thus, the value of $$\frac{d}{dx} \left( \frac{h(x)}{x} \right)$$ at $$x = 2$$ is: $$\boxed{-\frac{7}{4}}.$$ Would you like more details or have any further questions? --- Here are 5 related questions to expand your understanding: 1. How do you differentiate the product of two functions using the product rule? 2. What is the derivative of $$\frac{1}{x}$$, and how does it relate to the quotient rule? 3. If $$h(x)$$ were a specific polynomial, how would that change the derivative calculation? 4. How would the quotient rule change if $$g(x)$$ were more complex than just $$x$$? 5. What are some practical applications of the quotient rule in physics or economics? **Tip:** Always check if you can simplify the quotient before applying the quotient rule. This can sometimes make differentiation easier.

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Math Problem Analysis

Mathematical Concepts

Calculus
Differentiation
Quotient Rule

Formulas

Quotient Rule: d/dx [f(x)/g(x)] = (g(x)f'(x) - f(x)g'(x)) / [g(x)]^2
Substitution for x = 2: d/dx [h(x)/x] = (x * h'(x) - h(x)) / x^2

Theorems

Quotient Rule

Suitable Grade Level

Grades 11-12 (High School Calculus)