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3 years ago

9

A 400-g sample of a radioactive substance is placed in a chamber to be tested. After 3 h,

1 answer:

muminat3 years ago

3 0

Answer:

You left out the quantity of grams remaining.

Step-by-step explanation:

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Rick has 12 action, 15 comedy, and 9 drama DVDS. find the ratio of action DVDS to the total of DVDS. Then explain its meaning ho

krek1111 [17]

Okay, to find the ratio, add up all the numbers of DVDs.
You should end up with 36 DVDs.

The question states that you need to find the ratio between the action DVDs and the total amount of DVDs.

The amount of action DVDs is 12.

Now take 32 and 12, the ratio of the action DVDs and the total amount of DVDs to get your ratio.

The ratio is 12 out of 31, or 12:32

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3 years ago

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On Friday, 278 fourth graders went on a field trip to the Arizona State museum. The staff divided them into 7 tour groups. Which

stiks02 [169]

There would be ABOUT 40 kids in each group :-)

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3 years ago

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D/d{cosec^-1(1+x²/2x)} is equal to

SIZIF [17.4K]

Step-by-step explanation:

$\large\underline{\sf{Solution-}}$

$\rm :\longmapsto\:\dfrac{d}{dx} {cosec}^{ - 1} \bigg( \dfrac{1 + {x}^{2} }{2x} \bigg)$

Let assume that

$\rm :\longmapsto\:y = {cosec}^{ - 1} \bigg( \dfrac{1 + {x}^{2} }{2x} \bigg)$

We know,

$\boxed{\tt{ {cosec}^{ - 1}x = {sin}^{ - 1}\bigg( \dfrac{1}{x} \bigg)}}$

So, using this, we get

$\rm :\longmapsto\:y = sin^{ - 1} \bigg( \dfrac{2x}{1 + {x}^{2} } \bigg)$

Now, we use Method of Substitution, So we substitute

$\red{\rm :\longmapsto\:x = tanz \: \rm\implies \:z = {tan}^{ - 1}x}$

So, above expression can be rewritten as

$\rm :\longmapsto\:y = sin^{ - 1} \bigg( \dfrac{2tanz}{1 + {tan}^{2} z} \bigg)$

$\rm :\longmapsto\:y = sin^{ - 1} \bigg( sin2z \bigg)$

$\rm\implies \:y = 2z$

$\bf\implies \:y = 2 {tan}^{ - 1}x$

So,

$\bf\implies \: {cosec}^{ - 1}\bigg( \dfrac{1 + {x}^{2} }{2x} \bigg) = 2 {tan}^{ - 1}x$

Thus,

$\rm :\longmapsto\:\dfrac{d}{dx} {cosec}^{ - 1} \bigg( \dfrac{1 + {x}^{2} }{2x} \bigg)$

$\rm \: = \: \dfrac{d}{dx}(2 {tan}^{ - 1}x)$

$\rm \: = \: 2 \: \dfrac{d}{dx}( {tan}^{ - 1}x)$

$\rm \: = \: 2 \times \dfrac{1}{1 + {x}^{2} }$

$\rm \: = \: \dfrac{2}{1 + {x}^{2} }$

<u>Hence, </u>

$\purple{\rm :\longmapsto\:\boxed{\tt{ \dfrac{d}{dx} {cosec}^{ - 1} \bigg( \dfrac{1 + {x}^{2} }{2x} \bigg) = \frac{2}{1 + {x}^{2} }}}}$

<u>Hence, Option (d) is </u><u>correct.</u>

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2 years ago

Miller has a painting that is 4 ft by 8 ft. What will the dimensions of the painting be if he scales it down by a factor of one-

natta225 [31]

The answer is C) 1 ft by 2 ft
You can take 4*0.25 and 8*0.25
You end up with 1 by 2

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4 years ago

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What the awnser pls help

nikitadnepr [17]

it looks like its

1,1

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3 years ago

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