Problem

Find the exact location of all the relative arid absolute extrema of the function. (Orc
\[
g(x)=5 x^{2}-20 \sqrt{x}
\]
$g$ has - Select---
at $(x, y)=$
$g$ has
--Select--
at $(x, y)=$
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Answer

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Answer

\(\boxed{\text{The function } g(x)=5 x^{2}-20 \sqrt{x} \text{ has a relative and absolute minimum at } (1, -15)}\)

Steps

Step 1 :First, we find the derivative of the function \(g(x)=5 x^{2}-20 \sqrt{x}\). The derivative is \(g'(x) = 10x - \frac{10}{\sqrt{x}}\).

Step 2 :Next, we set the derivative equal to zero and solve for x to find the critical points. The critical point is \(x = 1\).

Step 3 :We substitute \(x = 1\) into the original function to get the corresponding y-value. The y-value is \(y = -15\). Therefore, the function has an extrema at \((1, -15)\).

Step 4 :To determine whether this is a relative or absolute extrema, and whether it is a maximum or minimum, we use the second derivative test. The second derivative of the function is \(g''(x) = 10 + \frac{5}{x^{\frac{3}{2}}}\).

Step 5 :The second derivative at the critical point is positive, which means the function is concave up at this point. Therefore, the function has a relative minimum at \((1, -15)\).

Step 6 :Since this is the only critical point of the function, it is also the absolute minimum. Therefore, the function \(g(x)=5 x^{2}-20 \sqrt{x}\) has a relative and absolute minimum at \((1, -15)\).

Step 7 :\(\boxed{\text{The function } g(x)=5 x^{2}-20 \sqrt{x} \text{ has a relative and absolute minimum at } (1, -15)}\)

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