Find the Laplace Transform of: 5 sin (3x) -

Answered question

2022-02-10

Find the Laplace Transform of: 5sin(3x)-17e-2x

Answer & Explanation

alenahelenash

alenahelenash

Expert2023-04-23Added 556 answers

To find the Laplace Transform of the function f(x)=5sin(3x)-17e-2x, we can use the definition of Laplace Transform, which is:

L{f(x)}=[0,]e-sxf(x)dx

where s is a complex number.

Using this definition, we can start by finding the Laplace Transform of each term separately, and then adding them together to get the Laplace Transform of the whole function.

L{5sin(3x)}=5[0,]e-sxsin(3x)dx

To evaluate this integral, we can use the formula:

eaxsin(bx)dx=(ba2+b2)eaxsin(bx)-(aa2+b2)eaxcos(bx)+C

where C is the constant of integration.

Applying this formula with a=-s and b=3, we get:

L{5sin(3x)}=5[3s2+32]=15s2+9

Now, let's find the Laplace Transform of the second term:

L{17e-2x}=17[0,]e-sxe-2xdx

We can simplify this expression by using the property:

ea+b=eaeb

which gives us:

e-sx-2x=e-(s+2)x

Using this property, we can write:

L{17e-2x}=17[0,]e-(s+2)xdx

This integral can be evaluated using the formula:

∫ e^(-ax) dx = -1/a * e^(-ax) + C

where C is the constant of integration.

Applying this formula with a=s+2, we get:

L{17e-2x}=17[-1s+2]=-17s+2

Finally, we can add the two Laplace Transforms to get the Laplace Transform of the original function:

L{5sin(3x)-17e-2x}=L{5sin(3x)}-L{17e-2x}=15s2+9-17s+2

Therefore, the Laplace Transform of the function f(x)=5sin(3x)-17e-2x is:

L{f(x)}=15s2+9-17s+2

Do you have a similar question?

Recalculate according to your conditions!

New Questions in Differential Equations

Ask your question.
Get an expert answer.

Let our experts help you. Answer in as fast as 15 minutes.

Didn't find what you were looking for?