1 / | | x*sin(2*x + 3) dx | / 0
Integral(x*sin(2*x + 3), (x, 0, 1))
Use integration by parts:
Let and let .
Then .
To find :
Let .
Then let and substitute :
The integral of a constant times a function is the constant times the integral of the function:
The integral of sine is negative cosine:
So, the result is:
Now substitute back in:
Now evaluate the sub-integral.
The integral of a constant times a function is the constant times the integral of the function:
Let .
Then let and substitute :
The integral of a constant times a function is the constant times the integral of the function:
The integral of cosine is sine:
So, the result is:
Now substitute back in:
So, the result is:
Add the constant of integration:
The answer is:
/ | sin(3 + 2*x) x*cos(3 + 2*x) | x*sin(2*x + 3) dx = C + ------------ - -------------- | 4 2 /
cos(5) sin(3) sin(5) - ------ - ------ + ------ 2 4 4
=
cos(5) sin(3) sin(5) - ------ - ------ + ------ 2 4 4
-cos(5)/2 - sin(3)/4 + sin(5)/4
Use the examples entering the upper and lower limits of integration.