Math Problem Statement

What is the slope of the line tangent to the graph of f, of, x, equals, start fraction, e, start superscript, minus, 4, x, end superscript, divided by, minus, 2, x, squared, end fractionf(x)= −2x 2

e −4x

​ at x, equals, 1, question markx=1? Express your answer in simplest form with no negative exponents.

Solution

To find the slope of the tangent line to the graph of f(x)=e4x2x2f(x) = \frac{e^{-4x}}{-2x^2} at x=1x = 1, we need to compute f(x)f'(x), the derivative of f(x)f(x), and evaluate it at x=1x = 1.

Step 1: Rewrite the function

The function is: f(x)=e4x2x2.f(x) = \frac{e^{-4x}}{-2x^2}.

Step 2: Apply the quotient rule

The quotient rule states: (u(x)v(x))=u(x)v(x)u(x)v(x)[v(x)]2.\left( \frac{u(x)}{v(x)} \right)' = \frac{u'(x)v(x) - u(x)v'(x)}{[v(x)]^2}. Here:

  • u(x)=e4xu(x) = e^{-4x}, so u(x)=4e4xu'(x) = -4e^{-4x} (by the chain rule).
  • v(x)=2x2v(x) = -2x^2, so v(x)=4xv'(x) = -4x (using the power rule).

Substituting these into the quotient rule: f(x)=(4e4x)(2x2)(e4x)(4x)(2x2)2.f'(x) = \frac{(-4e^{-4x})(-2x^2) - (e^{-4x})(-4x)}{(-2x^2)^2}.

Step 3: Simplify the numerator

Expand the numerator: (4e4x)(2x2)=8x2e4x,(-4e^{-4x})(-2x^2) = 8x^2e^{-4x}, (e4x)(4x)=4xe4x.(e^{-4x})(-4x) = -4xe^{-4x}. Thus, the numerator becomes: 8x2e4x(4xe4x)=8x2e4x+4xe4x.8x^2e^{-4x} - (-4xe^{-4x}) = 8x^2e^{-4x} + 4xe^{-4x}.

Step 4: Simplify the denominator

The denominator is: (2x2)2=4x4.(-2x^2)^2 = 4x^4.

Thus, the derivative is: f(x)=8x2e4x+4xe4x4x4.f'(x) = \frac{8x^2e^{-4x} + 4xe^{-4x}}{4x^4}.

Step 5: Factor and simplify

Factor out 4xe4x4xe^{-4x} from the numerator: f(x)=4xe4x(2x+1)4x4.f'(x) = \frac{4xe^{-4x}(2x + 1)}{4x^4}. Cancel 4x4x from the numerator and denominator (note x0x \neq 0): f(x)=e4x(2x+1)x3.f'(x) = \frac{e^{-4x}(2x + 1)}{x^3}.

Step 6: Evaluate at x=1x = 1

Substitute x=1x = 1 into f(x)f'(x): f(1)=e4(1)(2(1)+1)13.f'(1) = \frac{e^{-4(1)}(2(1) + 1)}{1^3}. Simplify: f(1)=e4(2+1)1=3e4.f'(1) = \frac{e^{-4}(2 + 1)}{1} = 3e^{-4}.

Final Answer:

The slope of the tangent line at x=1x = 1 is: 3e4\boxed{3e^{-4}}

Would you like further clarification or details? 😊


Related Questions:

  1. How does the quotient rule work, and why is it applied here?
  2. What is the significance of simplifying expressions with negative exponents?
  3. How do we interpret the slope of a tangent line geometrically?
  4. Can the slope of a tangent line be zero? If so, under what conditions?
  5. What is the difference between a derivative and a tangent line?

Tip: Always double-check your derivative calculations for complex functions, as small mistakes can propagate through the solution.

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Math Problem Analysis

Mathematical Concepts

Calculus
Derivatives
Tangent Lines
Quotient Rule

Formulas

Quotient Rule: (u(x)/v(x))' = (u'(x)v(x) - u(x)v'(x)) / [v(x)]^2
Derivative of e^(ax): e^(ax) * a

Theorems

Quotient Rule
Derivative of Exponential Functions

Suitable Grade Level

Grades 11-12