What is the integral of e^-(x/2) * sin(a*x) dx?

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In summary, the integral of e^-(x/2) * sin(a*x) dx is (-2/a) * e^-(x/2) * cos(a*x) + C, where C is the constant of integration. This integral can be solved using various techniques, including integration by parts and substitution. It is commonly used in mathematical models related to oscillatory systems and damped harmonic motion to calculate displacement or energy.
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Emmanuel_Euler
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what is the integral of e^-(x/2) * sin(a*x) dx??
 
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This looks enough like a schoolwork question that it needs to be re-posted in the Homework Help, Calculus & Beyond forum, and you need to show your efforts at working toward a solution.
 
  • #3
Do an "integration by parts" twice. Start by letting [itex]u= e^{-x/2}[/itex] and [itex]dv= sin(ax)dx[/itex]
 

FAQ: What is the integral of e^-(x/2) * sin(a*x) dx?

What is the integral of e^-(x/2) * sin(a*x) dx?

The integral of e^-(x/2) * sin(a*x) dx is (-2/a) * e^-(x/2) * cos(a*x) + C, where C is the constant of integration.

How do you solve the integral of e^-(x/2) * sin(a*x) dx?

To solve this integral, we can use the integration by parts method. Let u = e^-(x/2) and dv = sin(a*x) dx. Then, du = (-1/2) * e^-(x/2) and v = (-1/a) * cos(a*x). Plugging these into the integration by parts formula, we get (-2/a) * e^-(x/2) * cos(a*x) - (-1/2a) * integral of e^-(x/2) * cos(a*x) dx. Solving for the integral, we get (-2/a) * e^-(x/2) * cos(a*x) + C.

What is the significance of e^-(x/2) * sin(a*x) in integrals?

e^-(x/2) * sin(a*x) is a common integrand in many mathematical models, including those related to oscillatory systems and damped harmonic motion. Its integral can be used to calculate the total displacement or energy in these systems.

Can the integral of e^-(x/2) * sin(a*x) dx be solved using substitution?

Yes, the integral can also be solved using substitution. Let u = -(x/2) and du = (-1/2) * dx. Then, the integral becomes (-2/a) * e^u * sin(a*x) du. We can then use the trigonometric identity sin(a*x) = (1/2i) * (e^(iax) - e^(-iax)) to rewrite the integral as (-1/ia) * (e^(iax) - e^(-iax)) * e^u du. Combining like terms and integrating, we get (-2/a) * e^-(x/2) * cos(a*x) + C.

Is there a general formula for the integral of e^-(x/2) * sin(a*x) dx?

Yes, there is a general formula for the integral of e^-(x/2) * sin(a*x) dx. It is (-2/a) * e^-(x/2) * cos(a*x) + C, where C is the constant of integration. This formula can be derived using various integration techniques, such as integration by parts or substitution.

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