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Vlad [161]
1 year ago
5

Please help me with the below question.

Mathematics
1 answer:
Snezhnost [94]1 year ago
6 0

6a. By the convolution theorem,

L\{t^3\star e^{5t}\} = L\{t^3\} \times L\{e^{5t}\} = \dfrac6{s^4} \times \dfrac1{s-5} = \boxed{\dfrac5{s^4(s-5)}}

6b. Similarly,

L\{e^{3t}\star \cos(t)\} = L\{e^{3t}\} \times L\{\cos(t)\} = \dfrac1{s-3} \times \dfrac s{1+s^2} = \boxed{\dfrac s{(s-3)(s^2+1)}}

7. Take the Laplace transform of both sides, noting that the integral is the convolution of e^t and f(t).

\displaystyle f(t) = 3 - 4 \int_0^t e^\tau f(t - \tau) \, d\tau

\implies \displaystyle F(s) = \dfrac3s - 4 F(s) G(s)

where g(t) = e^t. Then G(s) = \frac1{s-1}, and

F(s) = \dfrac3s - \dfrac4{s-1} F(s) \implies F(s) = \dfrac{\frac3s}{\frac{s+3}{s-1}} = 3\dfrac{s-1}{s(s+3)}

We have the partial fraction decomposition,

\dfrac{s-1}{s(s+3)} = \dfrac13 \left(-\dfrac1s + \dfrac4{s+3}\right)

Then we can easily compute the inverse transform to solve for f(t) :

F(s) = -\dfrac1s + \dfrac4{s+3}

\implies \boxed{f(t) = -1 + 4e^{-3t}}

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Please help!! Math | 25 points :)
arlik [135]

Values of the composite function:

(g\cdot f)(-1)=6

(g\cdot f)(0)=7

(f\cdot g)(-1)=3

(f\cdot g)(4)=2

Step-by-step explanation:

Given two functions f(x) and g(x), their composite function is given by

(f\cdot g)(x) = f(g(x))

Which means using the output value of g(x) as input for f(x).

Let's start by computing

(g\cdot f)(-1)

First, we compute the value of f(-1), which is (from the graph)

f(-1) = 1

Now we use this value as input into g(x); we notice that at x = 1, the value of g(x) is 6, therefore:

(g\cdot f)(-1)=6

Now we evaluate

(g\cdot f)(0)

First, we compute the value of f(0), which is (from the graph)

f(0) = 0

Now we use this value as input into g(x); at x = 0, the value of g(x) is 7, therefore:

(g\cdot f)(0)=7

Now we evaluate

(f\cdot g)(-1)

First, we compute the value of g(-1), which is (from the graph)

g(-1) = 5

Now we use this value as input into f(x); at x = 5, the value of f(x) is 3, therefore:

(f\cdot g)(-1)=3

Finally we evaluate

(f\cdot g)(4)

First, we compute the value of g(4), which is (from the graph)

g(4) = 4

Now we use this value as input into f(x); at x = 4, the value of f(x) is 2, therefore:

(f\cdot g)(4)=2

Learn more about composite functions:

brainly.com/question/2723982

brainly.com/question/2456302

brainly.com/question/1949601

brainly.com/question/1900154

#LearnwithBrainly

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Ugo [173]

Answer:

84

Step-by-step explanation:

The mean is calculated as

mean = \frac{sum}{count} , then

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sum = 84

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ANEK [815]
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On Friday, the temperature changes -30 each hour. If the temperature changed for 7 hours, what is the total temperature change?
Marina86 [1]

A -120 difference will be seen in the temperature within a 7 hour period

<u>Equation</u>

<em>-</em>30 x 7

<em>Multiplying two of different signs ( - + ,  + - ) will always be negative.</em>

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