A curve has the equation 3x2+xy+y2=203x^2 + xy + y^2 = 203x2+xy+y2=20
The gradient of the tangent to the curve is 43\displaystyle \frac{4}{3}34 at the points P P\,P and QQQ.
Show that 2x+y=02x + y = 02x+y=0 at P P\,P and QQQ.
Find the coordinates of P P\,P and QQQ.