$\text{ A tangent is drawn to the parabola }{y}^2=4x\text{ at the point }P\text{ whose abscissa lies in the interval }[1,4]\text{ . The maximum }$

$\text{ possible area of the triangle formed by the tangent at }P\text{ , the ordinates of the point }P,\text{ and the }x\text{ -axis is equal to }$