Question

The co-ordinates of the extremities of the latus rectum of the parabola $5y^2=4x$ are

• A. $(\frac{1}{5}.\frac{2}{5}),(\frac{-1}{5},\frac{2}{5})$
• B. $(\frac{1}{5}.\frac{2}{5}),(\frac{1}{5},\frac{-2}{5})$
• C. $(\frac{1}{5}.\frac{4}{5}),(\frac{1}{5},\frac{-4}{5})$
• D. None of these

Answer 1

The correct option is B

$(\frac{1}{5}.\frac{2}{5}),(\frac{1}{5},\frac{-2}{5})$

$y^2=4.\frac{1}{5}x;a=\frac{1}{5}$ . Focus is $(\frac{1}{5},0)$ and co-ordinates of latus rectum are $y^2=\frac{4}{25}\Rightarrow y=\pm \frac{2}{5}$

or end points of latus rectum are $(\frac{1}{5},\pm \frac{2}{5})$ .