Skelly4444
Junior Member
- Joined
- Apr 4, 2019
- Messages
- 63
I have attached my workings for this difficult integration question together with a printout from an online integral calculator.
My question to the forum is that when we use the substitution x=3sin(u) why is the online integral calculator not acknowledging the negative sign in front of the 3cos(u)
Surely if you differentiate x=3sin(u) then dx/du would be -3cos(u) ??
I have been replacing dx with -3cos(u)du but the online integral calculator doesn't include the negative sign and so our answers differ?
Any ideas would be appreciated.
My question to the forum is that when we use the substitution x=3sin(u) why is the online integral calculator not acknowledging the negative sign in front of the 3cos(u)
Surely if you differentiate x=3sin(u) then dx/du would be -3cos(u) ??
I have been replacing dx with -3cos(u)du but the online integral calculator doesn't include the negative sign and so our answers differ?
Any ideas would be appreciated.