Friday, September 13, 2019

int (x^3 - 3x^2 + 5)/(x - 3) dx Find the indefinite integral.

int (x^3-3x^2+5)/(x-3)dx
To solve, divide the numerator by the denominator.
= int (x^2 + 5/(x-3))dx
Express it as sum of two integrals.
= int x^2dx + int 5/(x-3)dx
For the first integral, apply the formula int x^n dx = x^(n+1)/(n+1) + C .
= x^3/3 + C + int 5/(x-3)dx
For the second integral, apply u-substitution method.
Let 
u = x-3
Differentiate the u.
du = dx
Then, plug-in them to the second integral.
=x^3/3+C +5 int 1/(x-3)dx
=x^3/3+C + 5int1/udu
Apply the integral formula int 1/xdx = ln|x| + C .
= x^3/3 + 5ln|u| + C
And, substitute back u = x - 3 .
= x^3/3+ 5ln|x-3| + C
 
Therefore, int (x^3-3x^2+5)/(x-3)dx = x^3/3+5ln|x-3|+C .

No comments:

Post a Comment

Why is the fact that the Americans are helping the Russians important?

In the late author Tom Clancy’s first novel, The Hunt for Red October, the assistance rendered to the Russians by the United States is impor...