# Definite integral making me wanna die

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#1
So the question is: evaluate Integral sign with 3 on the top 1 on the bottom and 2x2-6/x3 dx

So I integrated it to 2x3/3 + 3x-2 then subbed in 3 then 1 and took them away from each other. Is this the correct method?

When I do it by hand I get 46/3 as an answer when I check it using my calculator's integral thing I get 44/3, why am I getting different answers, please help ;/ thanks!
0
5 years ago
#2
(Original post by Qaiys)
So the question is: evaluate Integral sign with 3 on the top 1 on the bottom and 2x2-6/x3 dx

So I integrated it to 2x3/3 + 3x-2 then subbed in 3 then 1 and took them away from each other. Is this the correct method?

When I do it by hand I get 46/3 as an answer when I check it using my calculator's integral thing I get 44/3, why am I getting different answers, please help ;/ thanks!

I get 44/3 too

what do you get in each bracket? 18 and a third in one and 3 and two thirds in the other.
0
5 years ago
#3
Well somewhere along the line you're subtracting a 2/3 less than you should be. You're integration is right, just probably dodgy stuff when you plug in the numbers. Try it again, super carefully. If it's still wrong, post the working.
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#4
(Original post by maggiehodgson)
I get 44/3 too

what do you get in each bracket? 18 and a third in one and 3 and two thirds in the other.
(Original post by FireGarden)
Well somewhere along the line you're subtracting a 2/3 less than you should be. You're integration is right, just probably dodgy stuff when you plug in the numbers. Try it again, super carefully. If it's still wrong, post the working.
Thank you both, I subbed the numbers in again for like the 1000th time and it worked finally -_- thank you both!
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