First slide

Parabola

Question

An equation of the latus rectum of the parabola
$x^{2} + 4 x + 2 y = 0$ is

Moderate

A

$y = \frac{- 3}{2}$
B

$y = \frac{2}{3}$
C

$y = \frac{3}{2}$
D

$y = \frac{- 2}{3}$

Solution

We can write the equation of the parabola as
$(x + 2)^{2} = - 2 (y - 2)$
Shifting the origin to (–2, 2), the equation is
$X^{2} = - 2 Y$ where $X = x + 2, Y = y - 2$
Equation of the latus rectum is $Y = - (\frac{2}{4}) = \frac{- 1}{2}$
$\Rightarrow y = \frac{3}{2}$ .

Get Instant Solutions

When in doubt download our app. Now available Google Play Store- Doubts App

Recieve an sms with download link

Doubts App

OR

SCAN ME

Doubts App

Doubts App