$\bf \textit{surface area of a sphere}\\\\ SA=4\pi r^2~~ \begin{cases} r=radius\\ \cline{1-1} SA=25\pi \end{cases}\implies 25\pi =4\pi r^2 \\\\\\ \cfrac{25\pi }{4\pi }=r^2\implies \cfrac{25}{4}=r^2\implies \sqrt{\cfrac{25}{4}}=r\implies \cfrac{\sqrt{25}}{\sqrt{4}}=r\implies \cfrac{5}{2}=r \\\\[-0.35em] ~\dotfill$

$\bf \textit{volume of a sphere}\\\\ V=\cfrac{4\pi r^3}{3}\qquad \qquad \implies V=\cfrac{4\pi \left( \frac{5}{2} \right)^3}{3}\implies V=\cfrac{4\pi \cdot \frac{125}{8}}{3}\implies V=\cfrac{\frac{500\pi }{8}}{~~\frac{3}{1}~~} \\\\\\ V=\cfrac{500\pi }{8}\cdot \cfrac{1}{3}\implies V=\cfrac{500\pi }{24}\implies V=\cfrac{125\pi }{6}\implies V\approx 65.45$

7 0

3 years ago

Decrease 18 tonnes by 30%

AVprozaik [17]

18 t - 18 t * 30% = 18 t - 17 * 0,3 = 18 t - 5,4 t = 12,6 t

5 0

3 years ago

A function g is defined by g:x→3−2sinx,for 0◦ ≤x≤A◦,where A is a constant.

Crank

<span>hmmm: g maps x onto 3-2sin(x) for all x from 0 to A degrees g(x) = 3-2sin(x) the inverse would have to be arcsin (3-x)/2, which only has a radian output between -pi and pi i believe. but this is just from memory</span>

6 0

4 years ago

Find the area of the blue shaded portion.

Debora [2.8K]

Answer:

its 48

Step-by-step explanation:

8 0

3 years ago

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