f(x) = ln(2x/x + 3)
1
dy/dx = ------------------------- * d(2x/(x+3))
2x/(x+3)
1 d(2x)*(x + 3) - 2x * d(x+3)
dy/dx = ---------------- * ------------------------------------- [ d(x+3) =1]
2x/(x+3) ( x + 3 )^2
2(x+3) - 2x
dy/dx = ----------------------------------------------
2x(x+3)
2x + 6 - 2x
dy/dx = -----------------------------
2x(x+3)
dy/dx = 6/(2x(x+3))