An example with answer I have goes;

x = 6 cos t

y = sqrt 11 sin t

Write down the equation of the conic & state what type of conic it is.

trig identity cos^{2}t + sin^{2}t = 1

which gives

x^{2}/ 6^{2}+ y^{2}/ (sqrt 11)^{2}= 1 . . . . . . . .

er! how does this happen, if you could help!