If the normal at an end of a latus rectum of an ellipse passes through an extremity of the minor axis, then the eccentricity e of the ellipse satisfies:
If the normal at an end of a latus rectum of an ellipse passes through an extremity of the minor axis, then the eccentricity e of the ellipse satisfies:
Option 1 -
e⁴ + 2e² – 1 = 0
Option 2 -
e² + e – 1 = 0
Option 3 -
e² + 2e – 1 = 0
Option 4 -
e⁴ + e² – 1 = 0
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1 Answer
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Correct Option - 4
Detailed Solution:Equation of normal to the ellipse x²/a² + y²/b² = 1 at (x? , y? ) is a²x/x? - b²y/y? = a² - b².
At the point (ae, b²/a):
a²x/ (ae) - b²y/ (b²/a) = a² - b²
It passes through (0, -b).
a² (0)/ (ae) - b² (-b)/ (b²/a) = a² - b²
ab = a² - b²
Since b² = a² (1-e²), a²-b² = a²e².
ab = a²e²
a²b² = a? e?
a² (a² (1-e²) = a? e?
1 - e² = e?
e? + e² - 1 = 0
Similar Questions for you
ae = 2b
Or 4 (1 – e2) = e2
4 = 5e2 ->
If two circles intersect at two distinct points
->|r1 – r2| < C1C2 < r1 + r2
| r – 2| < < r + 2
|r – 2| < 5 and r + 2 > 5
–5 < r 2 < 5 r > 3 … (2)
–3 < r < 7 (1)
From (1) and (2)
3 < r < 7
x2 – y2 cosec2q = 5
x2 cosec2q + y2 = 5
and
->
1 + sin2q = 7 – 7 sin2q
->8sin2q = 6
->
->

Slope of axis =
⇒ 2y – 6 = x – 2
⇒ 2y – x – 4 = 0
2x + y – 6 = 0
4x + 2y – 12 = 0
α + 1.6 = 4 ⇒ α = 2.4
β + 2.8 = 6 ⇒ β = 3.2
Ellipse passes through (2.4, 3.2)
⇒
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