Question
Question: The equation of the tangent at the vertex of the parabola x<sup>2</sup>+4x+2y = 0 is...
The equation of the tangent at the vertex of the parabola x2+4x+2y = 0 is
A
x = –2
B
x = 2
C
y = 2
D
y = – 2
Answer
y = 2
Explanation
Solution
The given equation can be written as (x + 2)2 = –2(y – 2).
Shifting the origin at (–2, 2) this equation becomes X2 = – 2Y,
where x = X – 2, y = Y +2.
The vertex of this parabola is at (–2, 2) and the tangent at the vertex is Y = 0 i.e. y = 2