integration question

[moe23]

can anyone please integrate this function from -1 to 0

(u^5-8u^3+10u^2)du

thanks a lot

 

[tkhunny]

A polynomial? u^5 ==> (1/6)u^6

You do the rest.

 

[moe23]

A polynomial? u^5 ==> (1/6)u^6

You do the rest.

hey tkhunny, if i intergrate the function i get:

(1/6)u^6-(2u^4)+(10/3)u^3

The problem is that i don't get the right answer when i put in the upper and lower limits (0, -1) into the the answer to solve the question. any ideas?

 

[Deleted member 4993]

A polynomial? u^5 ==> (1/6)u^6

You do the rest.

hey tkhunny, if i intergrate the function i get:

(1/6)u^6-(2u^4)+(10/3)u^3 <<< Correct

The problem is that i don't get the right answer when i put in the upper and lower limits (0, -1) into the the answer to solve the question. any ideas?

Please show the steps. You must be making your mistake when you are putting in u = -1 (for u = 0 the function becomes zero - hard to make mistake)

 

[moe23]

hey, so what i get is:

[0]-[(1/6)(-1)^6-(2(-1)^4)+(10/3)(-1)^3 = [0]-[1/6 - 2 - 10/3] = [0]-[-31/6] = 31/6 (my answer)

Thoughts?

 

[Mrspi]

hey, so what i get is:

[0]-[(1/6)(-1)^6-(2(-1)^4)+(10/3)(-1)^3 = [0]-[1/6 - 2 - 10/3] = [0]-[-31/6] = 31/6 (my answer)

Thoughts?

Yes....here's my thought.

(1/6) - 2 - (10/3) is NOT -31/6

Recheck your arithmetic....

 

[moe23]

hey, but i still get the same answer. what am i doing wrong with the arthimetic?

 

[Mrspi]

hey, but i still get the same answer. what am i doing wrong with the arthimetic?

OOPS....I get -31/6 too!

Sorry about that.

 

[Deleted member 4993]

How do know you this is not the correct answer? Do you know the "correct" answer?

 

[moe23]

i don't know the correct answer, but the application that i put this answer in marks it wrong.

 

[galactus]

How about 31/6...without the negative?.

 

[moe23]

How about 31/6...without the negative?.

that was my answer in the beginning but it was incorrect...

 

[moe23]

any other ideas or is that the answer everyone is coming 2?

 

[Mrspi]

i don't know the correct answer, but the application that i put this answer in marks it wrong.

Aw gee...yet another "encounter of the third kind" with one of these online courses?

 

[moe23]

lol i guess so.

 

[mmm4444bot]

The solution to your original post is 31/6.

If your machine teacher doesn't like that, then either the machine is expecting the number 31/6 in some undisclosed, alternate form OR the machine did not provide the correct exercise to begin with OR some sloppy programmer committed an error in logic OR "who knows?".

These are the sort of issues that you can expect, when you take a class taught by a machine.

 

[tkhunny]

To sum up:

1) The correct result is 31/6.

2) A quick check of the geometry shows ONLY non-negative values on [-1,0]. Result cannot be negative.

3) Not all exams or checks or answers in the back of the book are correct. Or, to be thorough, the "answer" may be correct but the problem statement is presented incorrectly. You must gain personal confidence and an ability to defend your work and maybe your grade.

4) You did not tell us the situation when you first posted. A better description of your efforts, in addition to the dispute with the automated checking system, would have been very useful information.