Which of the following expressions is not a valid antiderivative of 1/x for x>0?

Question

Which of the following expressions is not a valid antiderivative of 1/x for x > 0?

ln(x+1)

ln(2x)

ln(x)-7

ln(5x) + 3

Answer 1

anti-derivative of 1/x = ln(x) + C,

where C is a constant determined by the bounds of the integral.

Since you don't know the bounds, there is only one valid answer of the form above.