Let \( Y=Y(x) \) be a curve lying in the first quadrant such that the area enclosed by the line \( Y-y=Y'(x)(X-x) \) and the co-ordinate axes, where \( (x,y) \) is any point on the curve, is always \( \dfrac{-y^2}{2Y'(x)}+1 ,\)\( Y'(x)\neq 0) \). If \( Y(1)=1 \), then \( 12Y(2) \) equals _______.
