Question

Evaluate ∫9xdx. Here C is the constant of integration. Use abs(x) to denote |x|.

Answer 1

First of all, we must remember that:

$\int\frac{1}{x}dx=\ln|x|+C$

$\int\frac{9}{x}dx=9\int\frac{1}{x}dx=9\ln|x|+C$

Answer:

9*ln(abs(x)) + C