Concept 44: I can determine the circumference of a circle and use the circumference of a circle to find its diameter and radius.
1 answer:
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Answer:
The standard parabola
y² = -18 x +27
Length of Latus rectum = 4 a = 18
Step-by-step explanation:
<u><em>Explanation:-</em></u>
Given focus : (-3 ,0) ,directrix : x=6
Let P(x₁ , y₁) be the point on parabola
PM perpendicular to the the directrix L
SP² = PM²
(x₁ +3)²+(y₁-0)² =
x₁²+6 x₁ +9 + y₁² = x₁²-12 x₁ +36
y₁² = -18 x₁ +36 -9
y₁² = -18 x₁ +27
The standard parabola
y² = -18 x +27
Length of Latus rectum = 4 a = 4 (18/4) = 18