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