1 / | | -3*x | 13*sin(3*x)*E dx | / 0
Integral((13*sin(3*x))*E^(-3*x), (x, 0, 1))
There are multiple ways to do this integral.
Let .
Then let and substitute :
The integral of a constant times a function is the constant times the integral of the function:
Let .
Then let and substitute :
Use integration by parts, noting that the integrand eventually repeats itself.
For the integrand :
Let and let .
Then .
For the integrand :
Let and let .
Then .
Notice that the integrand has repeated itself, so move it to one side:
Therefore,
Now substitute back in:
So, the result is:
Now substitute back in:
Let .
Then let and substitute :
The integral of a constant times a function is the constant times the integral of the function:
Use integration by parts, noting that the integrand eventually repeats itself.
For the integrand :
Let and let .
Then .
For the integrand :
Let and let .
Then .
Notice that the integrand has repeated itself, so move it to one side:
Therefore,
So, the result is:
Now substitute back in:
Now simplify:
Add the constant of integration:
The answer is:
/ | -3*x -3*x | -3*x 13*cos(3*x)*e 13*e *sin(3*x) | 13*sin(3*x)*E dx = C - ----------------- - ----------------- | 6 6 /
-3 -3 13 13*cos(3)*e 13*e *sin(3) -- - ------------- - ------------- 6 6 6
=
-3 -3 13 13*cos(3)*e 13*e *sin(3) -- - ------------- - ------------- 6 6 6
13/6 - 13*cos(3)*exp(-3)/6 - 13*exp(-3)*sin(3)/6
Use the examples entering the upper and lower limits of integration.