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3 years ago

Find y as a function of x if y"' + 9y' = 0, y(0) = 6, y'(0) = 9, y"(0) = 18. y(x) =

Mathematics

1 answer:

Andreas93 [3]3 years ago

4 0

Answer:

y(x) = 8 - 2cos 3x + 3sin 3x

Step-by-step explanation:

Given the equation:

y''' + 9y' = 0

The characteristic equation :

⇒r³ + 9r =0

Solving for r, we get r = 0 and r = ± 3i

The general equation for such equation is :

y = C₁ + C₂cos 3x + C₃sin 3x

Given:

y(0) = 6

Thus, Applying in the above equation, we get

6 = C₁ + C₂ .......................................................1

Differentiating y , we get:

y' = -3C₂sin 3x + 3C₃cos 3x

Given:

y'(0) = 9

Thus, Applying in the above equation, we get

9 = 3C₃

or,

C₃ = 3

Differentiating y' , we get:

y'' = -9C₂cos 3x - 9C₃sin 3x

Given:

y''(0) = 18

Thus, Applying in the above equation, we get

18 = -9C₂

or,

C₂ = -2

Applying in equation 1 , we get:

C₁ = 8

Thus,

y(x) = 8 - 2cos 3x + 3sin 3x

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PolarNik [594]

The equation of the sinusoidal function is y = -2sin(x + 1.5) - 3

<h3>The sinusoidal function</h3>

The minimum and the maximum of the function are

Minimum = -1
Maximum = -5

The amplitude (A) is calculated as:

A = 0.5 * (Maximum - Minimum)

So, we have:

A = 0.5 * (-5 + 1)

A = -2

The vertical shift (d) is calculated as:

d = 0.5 * (Maximum + Minimum)

So, we have:

d = 0.5 * (-5 - 1)

d = -3

The period (P) is calculated as:

P = 2π/B

From the graph,

B = 1

So, we have:

P = 2π/1

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<h3>The equation of the sine function</h3>

In (a), we have:

A = -2

B = 1

d = -3

A sine function is represented as:

y = A sin(Bx + C) + D

So, we have:

y = -2sin(x + C) - 3

The graph passes through the point (0, -5)

So, we have

-5 = -2sin(0 + C) - 3

Solve for C, we have

C = 1.5

So, we have:

y = -2sin(x + 1.5) - 3

Hence, the equation of the sinusoidal function is y = -2sin(x + 1.5) - 3

Read more about sinusoidal function at

brainly.com/question/10700288

#SPJ1

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1 year ago

You flipped a coin 50 times and got 23 heads.What is the experimental probability of getting a head? Write your answer as a frac

lys-0071 [83]

Answer:

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Step-by-step explanation:

This problem is stating that every fifty times you flip a coin you get 23 heads. Finding the fraction is simple, it would be 23/50 because it is expressing the probability. The problem clearly states that every 50 times you get 23 heads. To find the decimal, take the fraction, 23/50, and multiply the numerator and denominator by 2. you get 46/100 which is 0.46. A percent is just a fraction out of a 100 which would make the percent 46.

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nexus9112 [7]

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