∫sqrt(x+4)/sqrt(x)
[m]xt^2-x=4[/m]
[m]x=\frac{4}{t^2-1}[/m]
[m]dx=(\frac{4}{t^2-1})`dt[/m]
[m]dx=-\frac{8t}{(t^2-1)^2}dt[/m]
[m] ∫ \sqrt{\frac{x+4}{x}} dx= ∫ t\cdot (-\frac{8t}{(t^2-1)^2})dt=-8 ∫t \cdot \frac{t}{(t^2-1)^2}dt
=[/m]