p143 q9 c
I have problem in (c). I get the answer 2x+y = 0 but the book says it is 2x+3y = 0
question:
consider an ellipse E:
and a line L :
I assume that you mean: 2x-3y+6=0
and D:
is a line parallel to L.
a) if D cuts E at
and
, show that
and
are the roots of the equation
b) find the range of values of c if E and D cut at (i) 2 points / (ii) 1 point
c) M is the mid - point of QR. Find the equation of the locus M as c varies.
here's my working in (c)
2x+y = 0
but answer says it's 2x+3y=0. what's wrong??? thanks!