Wednesday, February 27, 2013

Calculus of a Single Variable, Chapter 8, 8.1, Section 8.1, Problem 20

int (4x - 2/(2x+3)^2)dx
To solve, express it as difference of two integrals.
= int 4x dx - int 2/(2x+3)^2dx
Then, apply negative exponent rule a^(-m)=1/a^m .
= int 4xdx - int 2(2x+3)^(-2)dx
For the second integral, apply the u-substitution method.

u = 2x + 3
du = 2dx

Expressing the second integral in terms of u variable, it becomes:
=int 4xdx - int (2x+3)^(-2) * 2dx
=int 4xdx - int u^(-2) du
For both integrals, apply the formula int x^ndx= x^(n+1)/(n+1)+C .
= (4x^2)/2 - u^(-1)/(-1) + C
=2x^2 + u^(-1) + C
= 2x^2 + 1/u + C
And, substitute back u = 2x + 3
=2x^2+1/(2x+3)+C

Therefore, int (4x - 2/(2x+3)^2)dx=2x^2+1/(2x+3)+C .

No comments:

Post a Comment

Summarize the major research findings of "Toward an experimental ecology of human development."

Based on findings of prior research, the author, Bronfenbrenner proposes that methods for natural observation research have been applied in ...