A curve has equation \(y = 2x + \frac{1}{(x-1)^2}\). Verify that the curve has a stationary point at \(x = 2\) and determine its nature.
Solution
To find the stationary point, we first differentiate the equation \(y = 2x + \frac{1}{(x-1)^2}\).
The derivative is \(\frac{dy}{dx} = 2 - 2(x-1)^{-3}\).
Substitute \(x = 2\) into \(\frac{dy}{dx}\):
\(\frac{dy}{dx} = 2 - 2(2-1)^{-3} = 2 - 2 = 0\).
This confirms a stationary point at \(x = 2\).
Next, we find the second derivative to determine the nature of the stationary point:
\(\frac{d^2y}{dx^2} = 6(x-1)^{-4}\).
Substitute \(x = 2\) into \(\frac{d^2y}{dx^2}\):
\(\frac{d^2y}{dx^2} = 6(2-1)^{-4} = 6\).
Since \(\frac{d^2y}{dx^2} > 0\), the stationary point at \(x = 2\) is a minimum.
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