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3 years ago

Use an angle sum identity to derive each double-angle identity.

1 answer:

4 0

$\ [cos(2\theta)]'=(2cos^2\theta-1)'=2(cos^2\theta)'-(1)'\\\\=2\cdot2cos\theta\cdot(-sin\theta)-0=-2\cdot2sin\theta cos\theta=\boxed{-2sin2\theta}\\\\Used:\\\ [f(x)-g(x)]'=f'(x)-g'(x)\\\{f[g(x)]\}'=f'[g(x)]\cdot g'(x)\\(cosx)'=-sinx\\sin2x=2sinxcosx$

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Find the factor pairs of 80? Please help me :,(

koban [17]

1,80
2,40
4,20
5,16
8,10

3 0

2 years ago

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Which number is a factor of 12 but not a multiple of 3?

Delvig [45]

First list all the factors of 12;

1, 2, 3, 4, 6, 12

now let's see which ones are multiples of 3;

3, 6, 12

so all we have left are numbers 1, 2 and 4.

hope that helps, God bless!

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3 years ago

The voltage in an electrical circuit is multiplied by itself each time it is reduced. The voltage is 27/125 of a volt and it has

alexgriva [62]

I belive this is the answer

x³ = 27/125; and

x = 3/5.

explanation:

Reducing the voltage 3 times would result in multiplying the unknown voltage, x, by itself 3 times; this gives us

x³.

The current voltage is 27/125; this gives us the equation

x³ = 27/125.

To solve this, take the cubed root of both sides:

∛(x³) = ∛(27/125)

x = (∛27)/(∛125)

x = (∛(3*3*3))/(∛(5*5*5))

x = 3/5

7 0

2 years ago

What is the probability a sample of 90 test takers will provide a sample mean test score within 10 points of the population mean

Elena-2011 [213]

Answer:

0.658 is the probability that a sample 90 test takers will provide a sample mean test score within 10 points of the population mean of 502.

Step-by-step explanation:

The following information is missing:

The standard deviation of population is 100.

We are given the following information in the question:

Population mean, μ = 502

Standard Deviation, σ = 100

Sample size, n = 90

Standard error =

$\dfrac{\sigma}{\sqrt{n}} = \dfrac{100}{\sqrt{90}} = 10.54$

Formula:

$z_{score} = \displaystyle\frac{x-\mu}{\sigma}$

P(test score within 10 points)

$P(492 \leq x \leq 512) \\\\= P(\displaystyle\frac{492 - 502}{10.54} \leq z \leq \displaystyle\frac{512-502}{10.54}) \\\\= P(-0.9487 \leq z \leq 0.9487)\\= P(z \leq 0.9487) - P(z < -0.9487)\\= 0.829 -0.171 = 0.658 = 65.8\%$

$P(492 \leq x \leq 512) = 65.8\%$

0.658 is the probability that a sample 90 test takers will provide a sample mean test score within 10 points of the population mean of 502.

7 0

2 years ago

What percent of 30 is 18

Marina CMI [18]

18 is 60 percent of 30. 3 percent is 10 percent of 30 so 3 x 6 equals 18.

4 0

2 years ago

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