1 / | | 2 | x*sin (x) dx | / 0
Integral(x*sin(x)^2, (x, 0, 1))
Use integration by parts:
Let and let .
Then .
To find :
Rewrite the integrand:
Integrate term-by-term:
The integral of a constant is the constant times the variable of integration:
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:
The result is:
Now evaluate the sub-integral.
Integrate term-by-term:
The integral of a constant times a function is the constant times the integral of the function:
The integral of is when :
So, the result is:
The integral of a constant times a function is the constant times the integral of the function:
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:
The integral of sine is negative cosine:
So, the result is:
Now substitute back in:
The integral of a constant times a function is the constant times the integral of the function:
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:
The integral of is when :
So, the result is:
Now substitute back in:
Let .
Then let and substitute :
The integral of is when :
Now substitute back in:
So, the result is:
So, the result is:
The result is:
Now simplify:
Add the constant of integration:
The answer is:
/ | 2 | 2 x cos(2*x) /x sin(2*x)\ | x*sin (x) dx = C - -- - -------- + x*|- - --------| | 4 8 \2 4 / /
2 2 sin (1) cos (1) cos(1)*sin(1) ------- + ------- - ------------- 2 4 2
=
2 2 sin (1) cos (1) cos(1)*sin(1) ------- + ------- - ------------- 2 4 2
Use the examples entering the upper and lower limits of integration.