0 / | | x*cos(2*x + 1) dx | / 0
Integral(x*cos(2*x + 1), (x, 0, 0))
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 cosine is sine:
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 sine is negative cosine:
So, the result is:
Now substitute back in:
So, the result is:
Add the constant of integration:
The answer is:
/ | cos(1 + 2*x) x*sin(1 + 2*x) | x*cos(2*x + 1) dx = C + ------------ + -------------- | 4 2 /
Use the examples entering the upper and lower limits of integration.