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2 years ago

General solution of equation sin x + sin 5x = sin 2x + sin 4x is

Mathematics

1 answer:

zaharov [31]2 years ago

7 0

Answer:

x=nπ3, n∈I

Step-by-step explanation:

sin x + sin 5x = sin 2x + sin 4x

⇒⇒ 2 sin 3x cos 2x = 2 sin 3x cos x

⇒⇒ 2 sin 3x(cos 2x - cos x) = 0

⇒ sin 3x=0 ⇒ 3x=nπ ⇒ x=nπ3⇒ sin 3x=0 ⇒ 3x=nπ ⇒ x=nπ3 , n∈I, n∈I

or cos 2x−cos x=0 ⇒ cos 2x=cos xcos 2x-cos x=0 ⇒ cos 2x=cos x

⇒ 2x=2nπ±x ⇒ x=2nπ, 2nπ3⇒ 2x=2nπ±x ⇒ x=2nπ, 2nπ3 , n∈I, n∈I

But solutions obtained by x=2nπx=2nπ , n∈I, n∈I or x=2nπ3x=2nπ3 , n∈I, n∈I are all involved in x=nπ3x=nπ3 , n∈I

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Answer with Step-by-step explanation:

We have to prove that

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By using Euler's identity, we get

$cos2\theta+isin2\theta=(cos\theta+isin\theta)^2$

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Then, we get

$sin2\theta=2sin\theta cos\theta$

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2 years ago

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sweet [91]

Answer:

The probability of you winning is 1/3

No, it is not a fair game

Step-by-step explanation:

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Please check attachment for this

Kindly note that the total number of possible outcomes is 36.

And in the attachment, sums which are divisible by 3 are circled.

The number of circles we can count is 12

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Is it a fair game?

No, it is not

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Answer:

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Answer:

The correct answer is

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Step-by-step explanation:

In a sample with a number n of people surveyed with a probability of a success of $\pi$ , and a confidence interval $1-\alpha$ , we have the following confidence interval of proportions.

$\pi \pm z\sqrt{\frac{\pi(1-\pi)}{n}}$

In which

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For this problem, we have that:

In a random sample of 300 circuits, 10 are defective. This means that $n = 300$ and $\pi = \frac{10}{300} = 0.033$

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The lower limit of this interval is:

$\pi - z\sqrt{\frac{\pi(1-\pi)}{300}} = 0.033 - 1.96\sqrt{\frac{0.033*0.967}{300}} = 0.0128$

The upper limit of this interval is:

$\pi + z\sqrt{\frac{\pi(1-\pi)}{300}} = 0.033 + 1.96\sqrt{\frac{0.033*0.967}{300}} = 0.0532$

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