Just blow it away.

Let $y=f(x)$ be a curve passing through $(4,3)$ such that slope of normal at any point lying in the first quadrant is negative and the normal and tangent at any point P cuts the $Y-axis$ at $A$ & $B$ respectively such that the midpoint of $AB$ is origin, then find the area enclosed by the curves $y = f(x),~y=|4.25-|x||~ \& ~ y=4.25-|2.125x|$