integration question (1 Viewer)

A2RAYA

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ok we just started integration and this question has come up and i keep getting close to the answer, but i never actually get it..the answer is 0.0126 and i keep getting something around 0.034....a little help?? :)

int(x2+x+3/3x5)dx with 3 and 4 as the endpoints
 

Calculon

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you split it up like such
(x<sup>2</sup>/3x<sup>5</sup>)+(x/3x<sup>5</sup>)+(3/3x<sup>5</sup>)
Then you simplify
(1/3x<sup>3</sup>)+(1/3x<sup>4</sup>)+(1/x<sup>5</sup>)

/4
| 1/3x<sup>3</sup>+1/3x<sup>4</sup>+1/x<sup>5</sup>dx
/3

[-1/(6x<sup>2</sup>) -1/(9x<sup>3</sup>) -1/(4x<sup>4</sup>)]
Then substute in

[-1/(6*4<sup>2</sup>) -1/(9*4<sup>3</sup>) -1/(4*4<sup>4</sup>)] - [-1/(6*3<sup>2</sup>) -1/(9*3<sup>3</sup>) -1/(4*3<sup>4</sup>)]

I haven't got a calculator near me, but that should give you the correct answer:)
 
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Sarah168

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hahaha I'm such an idiot, I have a calculator in front of me so i calculated that whole damn thing out...i got 0.0226...:confused:

but knowing me, I probably made some stupid silly mistake and messed it up :p
 

clive

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Originally posted by Calculon

I haven't got a calculator near me, but that should give you the correct answer:)
Yes, it gives the correct answer - i just checked it with my calculator:)
 

Sarah168

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damn! me and my silly mistakes...:mad:

I always make silly mistakes in exams, even after checking and re doing most of the questions when i have the time...
 
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xeriphic

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i got 0.012571, same as clive

here was my calculation after calculon

= [-1/96-1/576-1/1024] - [-1/54-1/243-1/324]

= [-0.013129] - [-0.0257]

= 0.012571
 

A2RAYA

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ahhhh k sweet.....i kept gettin close but didnt get it......i thought the answer might have been wrong in the textbook, but guess not
 

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