Which of the following can be the parametric equation of (x−1)2=−36(y−4)
The parametric equation of
x2=−4ay are x=2at and y=−at2
⇒For (x−1)2=−4×9(y−4),
Where X=x−1,a=9,Y=y−4
So, X=2at and Y=−at2
x−1=2×9×t and y−4 =−9t2
⇒x=1+18t and y=4−9t2
Hence, the correct answer is Option a.