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3 years ago

Find the surface area of a hemisphere with a diameter of 26 cm. Round your answer to the nearest tenth.

1 answer:

4 0

The surface area of a sphere is $4 \pi r^{2}$ .

Hence, the surface area of a hemisphere is half that, $2 \pi r^{2}$ .

If the base is also included then the surface area will be $3 \pi r^{2}$ .

Given,

Diameter = 26 cm

Therefore, Radius = $\frac{26}{2}$ = 13 cm

Thus,

Area = $3 * \pi * 13^{2} = 3 * \pi * 169 = 507 \pi =$ = 1592.8 $cm^{2}$ [approx.]

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Ivahew [28]

Check the picture below.

$\bf \textit{Law of Cosines}\\ \quad \\
c^2 = {{ a}}^2+{{ b}}^2-(2{{ a}}{{ b}})cos(C)\implies 
c = \sqrt{{{ a}}^2+{{ b}}^2-(2{{ a}}{{ b}})cos(C)}
\\\\\\
\cfrac{{{ a}}^2+{{ b}}^2-c^2}{2{{ a}}{{ b}}}=cos(C)\implies cos^{-1}\left(\cfrac{{{ a}}^2+{{ b}}^2-c^2}{2{{ a}}{{ b}}}\right)=\measuredangle C\\\\
-------------------------------\\\\
\begin{cases}
d=10\\
e=18\\
f=22
\end{cases}\implies cos^{-1}\left(\cfrac{{{ 18}}^2+{{ 22}}^2-10^2}{2(18)(22)}\right)=\measuredangle D$

$\bf \implies cos^{-1}\left(0.893\overline{93}\right)=\measuredangle D\implies 26.63^o\approx \measuredangle D$

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4 years ago

Which method correctly solves the equation using the multiplication property of equality and the reciprocal of One-third? One-th

Airida [17]

Answer:

Step-by-step explanation:

Given the equation $\frac{1}{3}(x+9) = -12$

Step 1;

Expand the bracket at the right hand side of the equation to have:

$\frac{1}{3}x +\frac{1}{3}(9) = -12\\\frac{1}{3}x+3=-12\\subtracting\ 3\ from\ both\ sides\\\frac{1}{3}x+3-3=-12-3\\\frac{1}{3}x=-15\\$

Taking the reciprocal of both sides:

$\frac{3}{x} = \frac{-1}{15} \\ cross\ multiplying\\-x =45\\x=-45$

4 0

4 years ago

Read 2 more answers

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juin [17]

Answer:

23×x

=23x

Hope it helps

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3 years ago

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Tcecarenko [31]

Answer:

Step-by-step explanation:

cuz if you pay attention to the y coordinate on f(x) it's 4 instead of 1 as in g(x). this means that y-coordinate is multiplied to 4 therefore 4g(x) and it is vertically shifted up 1 unit and therefore the equation would be

f(x) = 4g(x) + 1

as g(x) = x²

f(x) = 4x² + 1

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3 years ago

Solve the differential equation using the method of undetermined coefficients

yuradex [85]

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3 years ago