Question
Question: The cartesian coordinates of the point on the parabola \(y^2 = -16x\), with, whose parameter is \(\f...
The cartesian coordinates of the point on the parabola y2=−16x, with, whose parameter is 21, are

A
(-2,4)
B
(4,-1)
C
(-1,-4)
D
(-1,4)
Answer
Option (3): (−1,−4).
Explanation
Solution
For the parabola y2=−16x, rewriting it in the form y2=4ax gives:
4a=−16⟹a=−4.The parametric equations for a parabola are:
x=at2,y=2at.For parameter t=21:
x=−4(21)2=−4(41)=−1,y=2(−4)(21)=−4.