Assignment:
Consider the curve given by x^2+4y^2 = 7 + 3xy
a) Show that there is a point P with x-coordinate 3 at which the line tangent to the curve at P is horizontal. Find the y-coordinate of P.
b) Find the value of d^2*y/d*x^2 at the point P found in part a).
Provide complete and step by step solution for the question and show calculations and use formulas.