Would it be because:Originally Posted by bigdoggy
If I evaluate an integral
or the constant can be brought outside:
which are different answers, how is this?
since the 3 is absorbed into the constant?
The reason I ask is because I've got this :which can be solved to give different answers:
how can this be so?
Not quite
int(dx/3x) is not ln(3x) but 1/3ln(3x) +c = 1/3ln(x) + c (1/3ln(3)is absorbed into c
To see this differentiate ln(3x) -- you don't get 1/3x
When integrating int(dx/3x) if you leave the 3 in the integral
you should use substitution u = 3x du = 3dx
1/3du = dx and you get 1/3int(1/udu)
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