int 1/(sqrt(x)-root3(x)) dx Use substitution and partial fractions to find the indefinite integral

int1/(sqrt(x)-root(3)(x))dx
Apply integral substitution:u=x^(1/6)
=>du=1/6x^(1/6-1)dx
du=1/6x^(-5/6)dx
du=1/(6x^(5/6))dx
6x^(5/6)du=dx
6(x^(1/6))^5du=dx
6u^5du=dx
int1/(sqrt(x)-root(3)(x))dx=int(6u^5)/(u^3-u^2)du
=int(6u^5)/(u^2(u-1))du
Take the constant out,
=6intu^3/(u-1)du
Integrand is an inproper rational function as degree of numerator is more than the degree of the denominator,
So let's carry out the division,
u^3/(u-1)=u^2+u+1+1/(u-1)
=6int(u^2+u+1+1/(u-1))du
Apply the sum rule,
=6(intu^2du+intudu+int1du+int1/(u-1)du)
Apply the power rule and the common integer:int1/xdx=ln|x|
=6(u^3/3+u^2/2+u+ln|u-1|)
Substitute back u=x^(1/6)
and add a constant C to the solution,
=6(1/3(x^(1/6))^3+1/2(x^(1/6))^2+x^(1/6)+ln|x^(1/6)-1|)+C
=2x^(1/2)+3x^(1/3)+6x^(1/6)+6ln|x^(1/6)-1|+C
=2sqrt(x)+3root(3)(x)+6root(6)(x)+6ln|root(6)(x)-1|+C
 

Comments

Popular posts from this blog

How does Bilbo show leadership and courage in The Hobbit?

What was the effect of World War II on African Americans?

How is Jack in William Golding's The Lord of the Flies presented as militaristic?