If vertex of a parabola is (2,-1) and the equation of its directrix is 4 x-3 y=21, then the length of its latus rectum is

Question

If vertex of a parabola is (2,-1) and the equation of its directrix is 4 x-3 y=21, then the length of its latus rectum is (A) 2 (B) 8 (C) 12 (D) 16

Tardigrade Admin · Accepted Answer

<img class="img-fluid question-image" alt="image" src="https://cdn.tardigrade.in/img/question/mathematics/c877b8d22940c252bf306415c0f38095-.png" /> a=(|8+3-21|/5)=(10/5)=2 ∴ latus rectum =4 a =8

Q. If vertex of a parabola is $(2, - 1)$ and the equation of its directrix is $4 x - 3 y = 21$ , then the length of its latus rectum is

2

8

12

16

$a = \frac{∣8 + 3 - 21∣}{5} = \frac{10}{5} = 2$
$∴$ latus rectum $= 4 a = 8$

Q. If vertex of a parabola is (2,−1) and the equation of its directrix is 4x−3y=21, then the length of its latus rectum is

2

8

12

16

a=5∣8+3−21∣​=510​=2 ∴ latus rectum =4a=8

Q. If vertex of a parabola is $(2, - 1)$ and the equation of its directrix is $4 x - 3 y = 21$ , then the length of its latus rectum is

$a = \frac{∣8 + 3 - 21∣}{5} = \frac{10}{5} = 2$
$∴$ latus rectum $= 4 a = 8$