The curves of the quadratic and cubic functions are f(x)=2x-x^2 and g(x)= ax^3 +bx^2+cx+d. where a,b,c,d ER, intersect at 2 points P and Q. These points are also two points of tangency for the two tangent lines drawn from point A(2,9) upon the parobala. The graph of the cubic function has a y-intercept at (0,-1) and an x intercept at (-4,0). Write the standard equations of the two tangent lines and determine the equation of the cubic function.