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Calculate f'(π/4) when f(x) = 2sin(x)

2 Answers

1 vote

Final answer:

The derivative of \
( f(x) = 2\sin(x) \) is
\( f'(x) = 2\cos(x) \). Evaluating at
\(x = (\pi)/(4)\), where
\(\cos((\pi)/(4)) = \sin((\pi)/(4)) = (√(2))/(2)\), results in
\( f'((\pi)/(4)) = √(2) \).

Explanation:

The derivative of the given function
\( f(x) = 2\sin(x) \) is determined using the chain rule, a fundamental concept in calculus. The chain rule stipulates that the derivative of a composite function is the product of the derivative of the outer function and the derivative of the inner function.

In this case, the outer function is the constant factor 2 multiplied by the sine function, and the inner function is
\(\sin(x)\). The derivative of
\(\sin(x)\) is
\(\cos(x)\), and when multiplied by the constant factor 2, the overall derivative becomes
\( f'(x) = 2\cos(x) \).

To find
\( f'((\pi)/(4)) \), we substitute (x) with
\((\pi)/(4)\) into the derivative expression. At
\(x = (\pi)/(4)\), both sine and cosine functions evaluate to
\((√(2))/(2)\). Multiplying this by the constant factor 2 gives
\( f'((\pi)/(4)) = 2 * (√(2))/(2) = √(2) \). Therefore, the derivative of
\( f(x) = 2\sin(x) \) at
\(x = (\pi)/(4)\) is equal to
\(√(2)\).

User Mlathe
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8.7k points
4 votes

Final Answer:

The derivative of f(x) = 2sin(x) evaluated at x = π/4 is f'(π/4) = √2.

Explanation:

To find the derivative of f(x) = 2sin(x), we use the derivative of the sine function, which is cos(x). Applying this to f(x), the derivative becomes f'(x) = 2cos(x). Now, to find f'(π/4), substitute π/4 into the derivative formula: f'(π/4) = 2cos(π/4).

Using the trigonometric identity cos(π/4) = √2 / 2, we get f'(π/4) = 2 * (√2 / 2) = √2. This result indicates the rate of change of the function 2sin(x) at x = π/4 is represented by the square root of 2.

The derivative represents the slope of the tangent line to the curve at a given point. In this case, f'(π/4) = √2 signifies that at x = π/4, the rate at which the function 2sin(x) is changing is √2. This rate of change is crucial in understanding how the function behaves at that specific point and helps in analyzing various aspects of its behavior around that point.

User MyStackRunnethOver
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9.0k points