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Homework Statement
I learned integration, but I think somewhere my technique is flawed, because I consistently get certain questions right and certain questions wrong. I don't know why I started doing it this way, but I always find DX by dividing it by DU and substitute it back into the equation. Where can I improve and what am I doing wrong?
Homework Equations
Here are two equations. First one I get right, second one wrong.
1) integral of (1 - 2x)^4 2dx
2) integral of ((5)(3t - 6)^2
The Attempt at a Solution
1)
U = 1 - 2x
DU = -2 dx
DX = DU/-2
(U)^4 (2)(DU/-2)
U^4 (-1)
-1 integral of (1/5) U^5 + C
= -1/5 (1-2x)^5 + c
RIGHT
2)
U = 3t - 6
DU = 3 dx
dx = (du/3)
5(u)^-2 du/3
1/3 5(u)^-1
(1/3) (-5/1) (3t - 6)^-1
WRONG
?
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