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4 years ago

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Analysis of the voltage in certain types of circuits involves terms of the form sin(nw^0t-90 degrees) where n is a positive inte

ger, w0 is the frequency of the voltage, and t is time. Use an identity to simplify this expression.
A.cscnw0t
B.-cscnw0t
C.cosnw0t
D.-cosnw0t

2 answers:

Leona [35]4 years ago

8 0

Answer:

d

Step-by-step explanation:

mel-nik [20]4 years ago

5 0

Answer:

D. -cos(nw0t)

Step-by-step explanation:

Subtracting 90° from the argument of the sine function shifts its graph 90° to the right, putting the negative peak on the y-axis. That corresponds to the negative cosine function, choice D.

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The square on the right is a scaled copy of the square on the left. Identify the scale factor. Express your answer in simplest f

Oksanka [162]

Square on the right is .9765 the measurements of the square on the left or 85:83

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3 years ago

Suppose that X is a random variable with mean 30 and standard deviation 4. Also suppose that Y is a random variable with mean 50

Vladimir79 [104]

Answer:

a) Var[z] = 1600

D[z] = 40

b) Var[z] = 2304

D[z] = 48

c) Var[z] = 80

D[z] = 8.94

d) Var[z] = 80

D[z] = 8.94

e) Var[z] = 320

D[z] = 17.88

Step-by-step explanation:

In general

V([x+y] = V[x] + V[y] +2Cov[xy]

how in this problem Cov[XY] = 0, then

V[x+y] = V[x] + V[y]

Also we must use this properti of the variance

V[ax+b] = $a^{2}$ V[x]

and remember that

standard desviation = $\sqrt{Var[x]}$

a) z = 35-10x

Var[z] = $10^{2}$ Var[x] = 100*16 = 1600

D[z] = $\sqrt{1600}$ = 40

b) z = 12x -5

Var[z] = $12^{2}$ Var[x] = 144*16 = 2304

D[z] = $\sqrt{2304}$ = 48

c) z = x + y

Var[z] = Var[x+y] = Var[x] + Var[y] = 16 + 64 = 80

D[z] = $\sqrt{80}$ = 8.94

d) z = x - y

Var[z] = Var[x-y] = Var[x] + Var[y] = 16 + 64 = 80

D[z] = $\sqrt{80}$ = 8.94

e) z = -2x + 2y

Var[z] = 4Var[x] + 4Var[y] = 4*16 + 4*64 = 320

D[z] = $\sqrt{320}$ = 17.88

7 0

3 years ago

The price of bread has been increasing over the last month. Brian believes there is a positive correlation between the number of

kotykmax [81]

Answer: Second Option

$m=0.09$

Step-by-step explanation:

The formula for calculating the average rate of change between two values of x ( $x_1$ and $x_2$ ) is:

$m=\frac{f(x_2)-f(x_1)}{x_2-x_1}$

$f (x_1)$ and $f (x_2)$ are the values of the function when $x = x_1$ and $x = x_2$

In this case

$x_1=3\\x_2=6$

Observe that when $x=3$ , $f(x) =2.41$ and when $x=6$ , $f(x)=2.68$

Finally the average rate of change from 3 to 6 storms is:

$m=\frac{2.68-2.41}{6-3}$

$m=0.09$

8 0

3 years ago

Read 2 more answers

For this special angle, draw the angle and find the reference angle: t= 2π/3

Nezavi [6.7K]

Answer:

C. And the reference angle is pi/3

Step-by-step explanation:

Let me give you a little quick way to do this. You’re probably trying to memorize the unit circle and figure out what 2pi/3 equals. However, all you need is a bit of math.

Start with the denominator and multiply the numerator by its correct angle

Anything with 3 in it’s denominator, is a multiple of a 60 degree angle. The numerator is 2 so do 60 x 2, which equals 120. Your angle is 120 and will land in the top left quadrant.

Moving on to the reference angle. Think of this as being what you have left on the horizontal axis. The angle took up 120 degrees. Now find the rest. 180 - 120 = 60. Pi/3 equals 60 degrees

3 0

3 years ago

Read 2 more answers

Someone please help me

Leno4ka [110]

Answer:b

Step-by-step explanation:

6 0

3 years ago