Solucionario Calculo Una Variable Thomas Finney Edicion 9 179 Link
The vertices of the box lie on the sphere, so each corner satisfies the equation
[ 4xR^2 - 3x^3 = 0 \quad\Longrightarrow\quad x\bigl(4R^2 - 3x^2\bigr) = 0. ] The vertices of the box lie on the
Maya had been wrestling with the problem all semester. It was the sort of question that seemed simple at first glance, then revealed hidden layers like an onion. The statement asked her to , using only one variable. In other words, the box’s height and the side of its base were tied together by the geometry of the sphere, and the challenge was to express the volume in terms of a single unknown, then locate its critical point. The statement asked her to , using only one variable
Setting the numerator to zero (the denominator never vanished inside the feasible interval) produced ] Factoring out the common denominator gave She
[ y = 2\sqrt{R^2 - \frac{1}{2}\Bigl(\frac{2R}{\sqrt{3}}\Bigr)^2} = 2\sqrt{R^2 - \frac{1}{2}\cdot\frac{4R^2}{3}} = 2\sqrt{R^2 - \frac{2R^2}{3}} = 2\sqrt{\frac{R^2}{3}} = \frac{2R}{\sqrt{3}}. ]
Factoring out the common denominator gave
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.
