Solucionario Calculo Una Variable Thomas Finney Edicion 9 179 Here

Factoring out the common denominator gave

[ V(x) = x^2 \cdot y = x^2 \cdot 2\sqrt{R^2 - \frac{x^2}{2}} = 2x^2\sqrt{R^2 - \frac{x^2}{2}} . ]

Plugging this back into the expression for : Factoring out the common denominator gave [ V(x)

Maya wrote the result in bold, underlined it, and added a small smiley face next to it—her personal signature of triumph. The next morning, the professor walked into the seminar room, a stack of papers in his hand. He asked the class to volunteer a solution for Exercise 179. Maya’s hand rose, heart thudding like a metronome.

She felt a surge of satisfaction. The problem had been reduced to a single‑variable function, exactly as the title promised. The next step was to find the maximum of (V(x)). Maya knew she needed the derivative (V'(x)) and the critical points where it vanished (or where the derivative was undefined). She set her mind to the task. He asked the class to volunteer a solution for Exercise 179

[ \left(\frac{x}{2}\right)^2+\left(\frac{x}{2}\right)^2+\left(\frac{y}{2}\right)^2 = R^2 . ]

She realized that the story of Exercise 179 wasn’t just about finding a maximum volume. It was about translating a three‑dimensional picture into algebra, about the elegance of a single variable governing a whole family of shapes, and about the quiet satisfaction that comes from turning a “hard problem” into a “solved puzzle”. The problem had been reduced to a single‑variable

[ 4xR^2 - 3x^3 = 0 \quad\Longrightarrow\quad x\bigl(4R^2 - 3x^2\bigr) = 0. ]