calculus
posted by Jane .
Consider curve given by
x^2+ 4y^2= 7 + 3xy..
Three part question
A) show that dy/dx = 3y2x/8y3x
B) Show that there is a point P with
xcoordinate 3 at whiich the line tangent to the curve at P is horizontal. Find the ycoordinate of P.
C) find the value of d^2y/ dx^2 at the point p found in part (B)

2x dx+8ydy=3ydx + 3xdy
solve for dy/dx
Then, take the next derivative.
for B), put x=3 into the original equation, find y. Then find the slope (dy/dx) at that point.