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inessss [21]
3 years ago
7

Sin8x=8sinxcosxcos2xcos4x proving trig identity?

Mathematics
1 answer:
weeeeeb [17]3 years ago
7 0
sin 8 x = 2 sin 4x  cos 4x =
= 2 * 2  sin 2x  cos 2x  cos 4 x =
= 4 * 2  sin x  cos x  cos 2x  cos 4x =
= 8  sin x  cos x  cos 2x  cos 4x    ( correct )  
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A photocopy machine can reduce copies to 80% of their original size. By copying an already reduced copy, further reductions can
alukav5142 [94]

<u>Part a)</u> if a page is reduced to 80%, what percent enlargement is needed to return it to its original size?

Let

x---------> the percent enlargement

we know that

the original size is the 100%

so

x*80%=100%

x=(100%/80%)

x=1.25--------> 1.25=(125/100)=125%

therefore

<u>the answer Part a) is</u>

the percent enlargement is 125%

<u>Part b)</u> Estimate the number of times in succession that a page must be copied to make the final copy less than 15% of the size of the original

we know that

A photocopy machine can reduce copies to 80% of their original size

so

Copy N 1

0.80*100%=80%

Copy N 2

0.80*80%=64%

Copy N 3

0.80*64%=51.2%

Copy N 4

0.80*51.2%=40.96%

Copy N 5

0.80*40.96%=32.77%

Copy N 6

0.80*32.77%=26.21%

Copy N 7

0.80*26.21%=20.97%

Copy N 8

0.80*20.97%=16.78%

Copy N 9

0.80*16.78%=13.42%-------------> 13.42% < 15%

therefore

<u>the answer Part b) is</u>

the number of times in succession is 9


6 0
3 years ago
A university has ten dormitories for students. All of the dormitories have students of similar ages and offer the same convenien
lina2011 [118]

Answer:

a is correct

Step-by-step explanation:

4 0
3 years ago
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mrs_skeptik [129]
Pretty sure you’ll save 1 dollar for b and and lose one dollar for a
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3 years ago
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____ [38]

Answer:

1/3

Step-by-step explanation:

The equation given to you is in y=mx+b form.

m is the slope which in this case would be 2/9.

b is the y-intercept which in this case would be 1/3

6 0
3 years ago
Read 2 more answers
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I think it’s 28 I’m not sure
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