Help please!!!??? Brainliest for explanation

A) Find a particular solution to y" + 2y = e^3 + x^3. b) Find the general solution.

Reptile [31]

Answer:

a.P.I= $\frac{e^{3x}}{11}+\frac{1}{2}(x^3-3x)$

b.G.S= $C_1Cos \sqrt2 x+C_2 Sin\sqrt2 x+\frac{1}{11}e^{3x}+\frac{1}{2}(x^3-3x}$

Step-by-step explanation:

We are given that a linear differential equation

$y''+2y=e^{3x}+x^3$

We have to find the particular solution

P.I= $\frac{e^{3x}}{D^2+2}+\frac{x^3}{D^2+2}$

P.I= $\frac{e^{3x}}{3^2+2}+\frac{1}{2} x^3(1+\frac{D^2}{2})^{-2}$

P.I= $\frac{e^{3x}}{11}+\frac{1-2\frac{D^2}{4}+3\frac{D^4}{16}+...}{2}x^3$

P.I= $\frac{e^{3x}}{11}+\frac{x^3-2\frac{\cdot3\cdot 2x}{4}}{2}+0}$ (higher order terms can be neglected

P.I= $\frac{e^{3x}}{11}+\frac{1}{2}(x^3-3x)$

b.Characteristics equation

$D^2+2=0$

$D=\pm\sqrt2 i$

C.F= $C_1cos \sqrt2x+C_2 sin\sqrt2 x$

G.S=C.F+P.I

G.S= $C_1Cos \sqrt2 x+C_2 Sin\sqrt2 x+\frac{1}{11}e^{3x}+\frac{1}{2}(x^3-3x)$

3 0

3 years ago

Jens garden Is 4feet wide and 4feet long.what is the area of jens garden

Sliva [168]

16 feet is the area

3 0

3 years ago

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Solve the equation by completing the square. Round to the nearest hundredth if necessary. x2 + 2x = 17

yawa3891 [41]

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Equation Given
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x² + 2x = 17

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Add the constant to make it perfect square
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x² + 2x + (2/2)² - ²(2/2)² = 17

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Evaluate the brackets
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x² + 2x + (1)² - ²(1)² = 17

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Form the perfect square
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(x + 1)² - 1 = 17

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Add 1 to both sides
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(x + 1)² = 17 + 1
(x + 1)² = 18

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Square root both sides
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√(x + 1)² = $\pm$ √18

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Solve for x
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x = 4.24 - 1 or - 4.24 -1

x = 3.24 or - 5.24 (nearest hundredth)

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Answer: x = x = 3.24 or - 5.24
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7 0

3 years ago

Find the solution of the differential equation that satisfies the given initial condition. y' tan x = 3a + y, y(π/3) = 3a, 0 &lt

Paladinen [302]

Answer:

$y(x)=4a\sqrt{3}* sin(x)-3a$

Step-by-step explanation:

We have a separable equation, first let's rewrite the equation as:

$\frac{dy(x)}{dx} =\frac{3a+y}{tan(x)}$

But:

$\frac{1}{tan(x)} =cot(x)$

So:

$\frac{dy(x)}{dx} =cot(x)*(3a+y)$

Multiplying both sides by dx and dividing both sides by 3a+y:

$\frac{dy}{3a+y} =cot(x)dx$

Integrating both sides:

$\int\ \frac{dy}{3a+y} =\int\cot(x) \, dx$

Evaluating the integrals:

$log(3a+y)=log(sin(x))+C_1$

Where C1 is an arbitrary constant.

Solving for y:

$y(x)=-3a+e^{C_1} sin(x)$

$e^{C_1} =constant$

So:

$y(x)=C_1*sin(x)-3a$

Finally, let's evaluate the initial condition in order to find C1:

$y(\frac{\pi}{3} )=3a=C_1*sin(\frac{\pi}{3})-3a\\ 3a=C_1*\frac{\sqrt{3} }{2} -3a$

Solving for C1:

$C_1=4a\sqrt{3}$

Therefore:

$y(x)=4a\sqrt{3}* sin(x)-3a$

3 0

3 years ago

(WORTH 20 POINTS)

tresset_1 [31]

So the function is
$f(x)=3( \frac{1}{3})^{ x }$
the intial value is where x=0
where x=0, the value of f(0)=3

grouth is 1/3 but it is decay, so it might be correct, or not because it is decay
it is exponential decay
true it is a stretch of the funciton f(x)=(1/3)^x
when x=3, then f(3)=1/9

the true things are

The function shows exponential decay.
The function is a stretch of the function f(x) = (1/3)x .

6 0

3 years ago

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