Integral of exp(7x)*sin(x) 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 e7xsin(x):
Let u(x)=sin(x) and let dv(x)=e7x.
Then ∫e7xsin(x)dx=7e7xsin(x)−∫7e7xcos(x)dx.
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For the integrand 7e7xcos(x):
Let u(x)=7cos(x) and let dv(x)=e7x.
Then ∫e7xsin(x)dx=7e7xsin(x)−49e7xcos(x)+∫(−49e7xsin(x))dx.
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Notice that the integrand has repeated itself, so move it to one side:
4950∫e7xsin(x)dx=7e7xsin(x)−49e7xcos(x)
Therefore,
∫e7xsin(x)dx=507e7xsin(x)−50e7xcos(x)
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Now simplify:
50(7sin(x)−cos(x))e7x
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Add the constant of integration:
50(7sin(x)−cos(x))e7x+constant
The answer is:
50(7sin(x)−cos(x))e7x+constant
The answer (Indefinite)
[src]
/
| 7*x 7*x
| 7*x cos(x)*e 7*e *sin(x)
| e *sin(x) dx = C - ----------- + -------------
| 50 50
/
∫e7xsin(x)dx=C+507e7xsin(x)−50e7xcos(x)
⟨−∞,∞⟩
=
⟨−∞,∞⟩
Use the examples entering the upper and lower limits of integration.