Integral of (x(6-x))/2 dx
The solution
Detail solution
-
The integral of a constant times a function is the constant times the integral of the function:
∫2x(6−x)dx=2∫x(6−x)dx
-
There are multiple ways to do this integral.
Method #1
-
Let u=−x.
Then let du=−dx and substitute du:
∫(u2+6u)du
-
Integrate term-by-term:
-
The integral of un is n+1un+1 when n=−1:
∫u2du=3u3
-
The integral of a constant times a function is the constant times the integral of the function:
∫6udu=6∫udu
-
The integral of un is n+1un+1 when n=−1:
∫udu=2u2
So, the result is: 3u2
The result is: 3u3+3u2
Now substitute u back in:
−3x3+3x2
Method #2
-
Rewrite the integrand:
x(6−x)=−x2+6x
-
Integrate term-by-term:
-
The integral of a constant times a function is the constant times the integral of the function:
∫(−x2)dx=−∫x2dx
-
The integral of xn is n+1xn+1 when n=−1:
∫x2dx=3x3
So, the result is: −3x3
-
The integral of a constant times a function is the constant times the integral of the function:
∫6xdx=6∫xdx
-
The integral of xn is n+1xn+1 when n=−1:
∫xdx=2x2
So, the result is: 3x2
The result is: −3x3+3x2
So, the result is: −6x3+23x2
-
Now simplify:
6x2(9−x)
-
Add the constant of integration:
6x2(9−x)+constant
The answer is:
6x2(9−x)+constant
The answer (Indefinite)
[src]
/
| 3 2
| x*(6 - x) x 3*x
| --------- dx = C - -- + ----
| 2 6 2
|
/
∫2x(6−x)dx=C−6x3+23x2
The graph
Use the examples entering the upper and lower limits of integration.