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Find derivative of

a.) f²(x)={-21 e⁷x}+14 e²x / (e⁵x}+1²
b.) f²(x)={49 e⁷x}+14 e²x / (e⁵x}+1

User DianaBG
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1 Answer

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Final Answer:

a.) The derivative of f²(x) is
\[ f'(x) = (-147e^(7x) + 28e^(2x))/((e^(5x) + 1)^2) \]

b.) The derivative of f²(x) is
\[ f'(x) = (343e^(7x) + 28e^(2x))/((e^(5x) + 1)^2) \]

Step-by-step explanation:

In both cases, we use the quotient rule to find the derivative. The quotient rule states that for a function
\[ g(x) = (u(x))/(v(x)) \], the derivative
\[ g'(x) \] is given by
\[ g'(x) = (u'v - uv')/(v^2) \].

For option a:


\[ u(x) = -21e^(7x) + 14e^(2x) \]


\[ v(x) = e^(5x) + 1 \]


\[ u'(x) = -147e^(7x) + 28e^(2x) \]


\[ v'(x) = 5e^(5x) \]

Using the quotient rule, we get the derivative
\[ f'(x) = (u'v - uv')/(v^2) = (-147e^(7x) + 28e^(2x))/((e^(5x) + 1)^2) \].

For option b:


\[ u(x) = 49e^(7x) + 14e^(2x) \]


\[ v(x) = e^(5x) + 1 \]


\[ u'(x) = 343e^(7x) + 28e^(2x) \]

\
[ v'(x) = 5e^(5x) \]

Using the quotient rule, we get the derivative
\[ f'(x) = (u'v - uv')/(v^2) = (343e^(7x) + 28e^(2x))/((e^(5x) + 1)^2) \].

These derivatives provide the rate at which the given functions change with respect to the variable x.

User Boston Kenne
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7.3k points