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3 years ago

15

Find the radius of the cylinder with height 6 cm with volume 54 cubic cm

2 answers:

inna [77]3 years ago

8 0

We know, Volume of a Cylinder = πr²h

Now, Substitute all the given values,
54 = 3.14 * r² * 6

54 = 18.84 * r²

r² = 54/18.84

r = √2.866

r = 1.7 [ After rounding-off ]

In short, Your Answer would be: 1.7 cm

Hope this helps!

Lubov Fominskaja [6]3 years ago

4 0

V = pi r^2 h
54 = 3.14 * r^2 * 6
54 = 18.84 r^2
Divide both sides by 18.84
r^2 = 2.866
Square root both sides
r = 1.7

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3 years ago

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3 years ago

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Answer:

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Step-by-step explanation:

First, we need to recall the definition of $\cos z$ when $z$ is a complex number:

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Then,

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Now, recall the definition of the complex exponential:

$e^{z}=e^{x+iy} = e^x(\cos y +i\sin y)$ .

So,

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$e^{-2i+3} = e^{3}(\cos 2-i\sin 2)$ (we use that $\sin(-y)=-\sin y)$ .

Thus,

$e^{2i-3}+e^{-2i+3} = e^{-3}\cos 2+ie^{-3}\sin 2 + e^{3}\cos 2-ie^{3}\sin 2)$

Now we group conveniently in the above expression:

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