Integral of e^(-2x)*sin(3x) dx
The solution
Detail solution
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Use integration by parts, noting that the integrand eventually repeats itself.
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For the integrand e−2xsin(3x):
Let u(x)=sin(3x) and let dv(x)=e−2x.
Then ∫e−2xsin(3x)dx=−∫(−23e−2xcos(3x))dx−2e−2xsin(3x).
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For the integrand −23e−2xcos(3x):
Let u(x)=−23cos(3x) and let dv(x)=e−2x.
Then ∫e−2xsin(3x)dx=∫(−49e−2xsin(3x))dx−2e−2xsin(3x)−43e−2xcos(3x).
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Notice that the integrand has repeated itself, so move it to one side:
413∫e−2xsin(3x)dx=−2e−2xsin(3x)−43e−2xcos(3x)
Therefore,
∫e−2xsin(3x)dx=−132e−2xsin(3x)−133e−2xcos(3x)
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Now simplify:
−13(2sin(3x)+3cos(3x))e−2x
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Add the constant of integration:
−13(2sin(3x)+3cos(3x))e−2x+constant
The answer is:
−13(2sin(3x)+3cos(3x))e−2x+constant
The answer (Indefinite)
[src]
/
| -2*x -2*x
| -2*x 3*cos(3*x)*e 2*e *sin(3*x)
| e *sin(3*x) dx = C - ---------------- - ----------------
| 13 13
/
13e−2x(−2sin(3x)−3cos(3x))
The graph
-2 -2
3 3*cos(3)*e 2*e *sin(3)
-- - ------------ - ------------
13 13 13
133−13e−2(2sin3+3cos3)
=
-2 -2
3 3*cos(3)*e 2*e *sin(3)
-- - ------------ - ------------
13 13 13
−13e22sin(3)−13e23cos(3)+133
Use the examples entering the upper and lower limits of integration.