Integration problem, stuck, not sure

Hello,

Covering the topic of Indefinite Integral:

I am doing a question, which my book does not give the answer and hoping someone can look at it and tell me if I did this right.

Integre/sign then ( x^2 + 4x + 4 ) ^ 1/3 dx

So I worked out 1/3 to the numbers in the brackets.

So I have Int Sign ( x^7/3 + 4 x^4/3 + 4^1/3)

then:

int sign x^7/3 dx + 4 intsign x^4/3 dx + 4^1/3 intsign dx

So my answer is

3/10 x^10/2 + 12/7 x^7/3 + 4^1/3 x + C.

is this correct? or not, thanks.

Joanne

Re: Integration problem, stuck, not sure

Hi Brady,

Quote:

So I worked out 1/3 to the numbers in the brackets.

So I have Int Sign ( x^7/3 + 4 x^4/3 + 4^1/3)

This is wrong as a polynomial cannot be broken down the way you have assumed it to.

This is how you can go about doing it so you are expected to evaluate

substitute and finish you integral.

Kalyan

Re: Integration problem, stuck, not sure

So is the answer

3/5(x+2)^5/3 + C ??

Thanks for the help, and correcting me as well.

Re: Integration problem, stuck, not sure

Quote:

Originally Posted by

**bradycat** So is the answer

3/5(x+2)^5/3 + C ??

Thanks for the help, and correcting me as well.

check the validity of an antiderivative by taking the derivative of your solution ...

Re: Integration problem, stuck, not sure

Oh I forgot about that, ya it's correct then.

Thanks

Joanne