at least curve sketching is easy, so dont worry about it. as for the harder 3 unit your going to need practice, so get some other text books like cambridge
P(acos@,bsin@) lies on the ellipse (x^2)/(a^2)+(y^2)/(b^2)=1. The Normal at P cuts the x axis at X and the Y axis at Y. Show that (PX)/(PY)=(b^2)/(a^2)
is the distance formula the only way to go about this one?