Math Problem Statement

If y = log2(x^2), then the value of dy/dx at x = e^(-1) is?

Solution

We are tasked with finding the derivative dydx\frac{dy}{dx} of the given function y=log2(x2)y = \log_2(x^2) at x=e1x = e^{-1}.


Step-by-step solution:

  1. Rewrite the function: The function is given as: y=log2(x2)y = \log_2(x^2) Recall that loga(b)=ln(b)ln(a)\log_a(b) = \frac{\ln(b)}{\ln(a)}. Therefore: y=ln(x2)ln(2)y = \frac{\ln(x^2)}{\ln(2)}

    Simplify further: y=2ln(x)ln(2)y = \frac{2\ln(x)}{\ln(2)}

  2. Differentiate yy with respect to xx: Using the constant multiplier rule and the derivative of ln(x)\ln(x): dydx=2ln(2)ddx(ln(x))\frac{dy}{dx} = \frac{2}{\ln(2)} \cdot \frac{d}{dx}(\ln(x)) Since ddx(ln(x))=1x\frac{d}{dx}(\ln(x)) = \frac{1}{x}, we get: dydx=2ln(2)1x\frac{dy}{dx} = \frac{2}{\ln(2)} \cdot \frac{1}{x} Thus: dydx=2xln(2)\frac{dy}{dx} = \frac{2}{x\ln(2)}

  3. Evaluate dydx\frac{dy}{dx} at x=e1x = e^{-1}: Substituting x=e1x = e^{-1} into dydx\frac{dy}{dx}: dydx=2(e1)ln(2)\frac{dy}{dx} = \frac{2}{(e^{-1})\ln(2)} Simplify the denominator: dydx=21eln(2)\frac{dy}{dx} = \frac{2}{\frac{1}{e} \cdot \ln(2)} dydx=2eln(2)\frac{dy}{dx} = \frac{2e}{\ln(2)}


Final Answer:

dydx=2eln(2)at x=e1.\frac{dy}{dx} = \frac{2e}{\ln(2)} \quad \text{at } x = e^{-1}.


Do you want further details or clarification?
Here are 5 related questions to explore further:

  1. How do we derive the formula loga(b)=ln(b)ln(a)\log_a(b) = \frac{\ln(b)}{\ln(a)}?
  2. Why is the derivative of ln(x)\ln(x) equal to 1x\frac{1}{x}?
  3. How do you compute the natural logarithm (ln\ln) of specific values like ln(2)\ln(2)?
  4. What are some other applications of logarithmic differentiation?
  5. What happens if we use a different base logarithm, like log10(x2)\log_{10}(x^2)?

Tip: Always simplify logarithmic expressions before differentiating—it makes the process easier and reduces errors.

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Math Problem Analysis

Mathematical Concepts

Logarithms
Natural Logarithms
Differentiation

Formulas

log_a(b) = ln(b) / ln(a)
d/dx(ln(x)) = 1/x
Derivative of logarithmic functions

Theorems

Change of Base Theorem for Logarithms
Rules of Differentiation

Suitable Grade Level

Grades 11-12