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Liula [17]
3 years ago
15

PLEASE HELP!!! I don’t understand

Mathematics
1 answer:
asambeis [7]3 years ago
3 0

Answer:

Step-by-step explanation:

Use the half angle identity for cosine:

cos(x/2)=+ or - sqrt(1+cos(x))/sqrt(2)

I'm going to figure out the sign part first for cos(x/2)...

so x is in third quadrant which puts x between 180 and 270

if we half x, x/2 this puts us between 90 and 135 (that's the second quadrant)

cosine is negative in the second quadrant

so we know that

cos(x/2)=-sqrt(1+cos(x))/sqrt(2)

Now we need cos(x)... since we are in the third quadrant cos(x) is negative...

If you draw a reference triangle sin(x)=3/5 you should see that cos(x)=4/5 ... but again cos(x)=-4/5 since we are in the third quadrant.

So let's plug it in:

cos(x/2)=-sqrt(1+4/5)/sqrt(2)

No one likes compound fractions (mini-fractions inside bigger fractions)

Multiply top and bottom inside the square roots by 5.

cos(x/2)=-sqrt(5+4)/sqrt(10)

cos(x/2)=-sqrt(9)/sqrt(10)

cos(x/2)=-3/sqrt(10)

Rationalize the denominator

cos(x/2)=-3sqrt(10)/10

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pantera1 [17]

Answer: The possible side lengths are either 16 inches or 20 inches

Step-by-step explanation: The aquarium is in the shape of a cube which suggests that, all dimensions (length, width and height) are equal.

If it can hold 4096 cubic inches of water, then the volume of water in it can be calculated as follows;

Volume = L x W x H

Knowing that all three dimensions are the same the formula can be re-written as;

Volume = L³

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Add the cube root sign to both sides of the equation

∛4096 = ∛L³

16 = L

Also if it can hold up to 8000 cubic inches of water, then the volume of water in it can be calculated as;

Volume = L³

8000 = L³

Add the cube root sign to both sides of the equation

∛8000 = ∛L³

20 = L

Therefore, if the aquarium can hold between 4096 and 8000 cubic inches of water, then the side lengths are either 16 inches or 20 inches

3 0
3 years ago
Help me with dis pls
Nataly_w [17]

Answer:

a. complementary

b. neither

c. supplementary

d. supplementary

e. supplementary   x=21

Step-by-step explanation:

CODE: cnsss21

3 0
3 years ago
What is the area of the regular octagon below?
pishuonlain [190]
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Please help on this equation I don't get it.
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Answer:

0.6 liters

Step-by-step explanation:

3 liters divided amongst 5 people comes to 0.6 liters per person. there are approximately 33.8 ounces in a liter so in ounces, everyone would get approximately 56.35 ounces of soda.

for a picture you could draw a cup with soda in it and label it to show the amount

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Since it's a multiple of 24, it has to be a multiple of the factors of 24.

Factors of 24:
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You can use some of this knowledge to help create the number.
Since the # needs to be a multiple off 2, the last digit needs to be an 8

All numbers that are multiples of 3 have the property that all of their digits added together have to be a number that is evenly divisible by 3.

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