=====Mathematics 250 - Spring 2016===== ==== Homework ==== **Section 9.4**: 9ab, 14, 15, 23, 24, 29, 30 Also: 1. Evaluate $\displaystyle{\int\int\int_B \frac{1}{\sqrt{x^2+y^2+z^2}} \ dV}$, where $B$ is the region in $\mathbb{R}^3$ between the spheres with equations $x^2 + y^2 + z^2 = 4$ and $x^2 + y^2 + z^2 = 9$. 2. Evaluate $\displaystyle{\int\int\int_B \sin\left(\sqrt{x^2+y^2+z^2}\right) \ dV}$, where $B$ is the region in $\mathbb{R}^3$ described by $x \ge 0$, $y \ge 0$, $z \ge 0$, and $x^2 + y^2 + z^2 \le 1$. 3. Evaluate $\displaystyle{\int\int\int_B e^{-\sqrt{x^2+y^2+z^2}} \ dV}$, where $B$ is the closed ball of radius 3 centered at the origin in $\mathbb{R}^3$. Answers: 1. $10\pi$ 2. $\frac{\pi}{2}(2\sin(1) + \cos(1) - 2)$ 3. $4\pi(2 - 17e^{-3})$