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Law Incorporation [45]
3 years ago
10

Isolate the identity cos 2x - cos 8x cos 2x + cos 8x HELP PLS

Mathematics
1 answer:
Nikolay [14]3 years ago
4 0

Answer:

Cos 2x = Cos (5x-3x)

Cos(5x)Cos(3x) + Sin(5x)Sin(3x)

Cos 8x = Cos (5x + 3x)

Cos(5x)Cos(3x) - Sin(5x)Sin(3x)

Cos 2x - Cos 8x

= Cos(5x)Cos(3x) + Sin(5x)Sin(3x) -

[Cos(5x)Cos(3x) - Sin(5x)Sin(3x)]

= 2Sin(5x)Sin(3x)

Cos 2x + Cos 8x

= Cos(5x)Cos(3x) + Sin(5x)Sin(3x) +

[Cos(5x)Cos(3x) - Sin(5x)Sin(3x)]

= 2Cos(5x)Cos(3x)

= 2Sin(5x)Sin(3x) ÷ 2Cos(5x)Cos(3x)

2 gets cancelled out

Sin(5x)/Cos(5x) is Tan(5x)

Sin(3x)/Cos(3x) is Tan(3x)

Hence the fraction is identical to

Tan(5x)Tan(3x)

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Katie wants to buy a bracelet. She only has $30 to spend. She has found a bracelet with a regular price of $45 and a discount of
11111nata11111 [884]

Given :

Money Katie has, M = $30.

She has found a bracelet with a regular price of $45 and a discount of 35%.

The sales tax is 7%.

To Find :

Will she have enough to buy the bracelet.

Solution :

Original price = $45 .

Price after discount = $( 45 - 45×0.35) = $29.25 .

Selling Price = $( 29.25 + 29.25×0.07 ) = $31.2975 .

Since, selling price is greater than $30.

Money needed = $( 31.2975 - 30 ) = $1.2975 .

Therefore, Katie will not buy the bracelet.

5 0
3 years ago
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victus00 [196]

Answer:

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Step-by-step explanation:

We have the equation r/7.1 = 4.2 and are asked to solve for r.

To solve, we need to isolate r, do as followed and multiply 7.1 from both sides:

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r = 29.82

8 0
3 years ago
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11th grade Algebra 2, please help.<br> If g(t) = 2/(t + 3) then g( blank) - 2/(4a + 3)
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Answer:

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