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A line L passing through the focus of th...

A line L passing through the focus of the parabola `(y-2)^(2)=4(x+1)` intersects the two distinct point. If m be the slope of the line I,, then

A

`min(-oo, -1)uu(1, oo)`

B

`m in (-oo, 0)uu(0, oo)`

C

`min(-oo, 0)uu(0, oo)`

D

none of these

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To solve the problem, we need to analyze the parabola given by the equation \((y - 2)^2 = 4(x + 1)\) and determine the range of slopes \(m\) for a line passing through the focus of the parabola that intersects it at two distinct points. ### Step-by-Step Solution: 1. **Identify the Standard Form of the Parabola**: The given equation \((y - 2)^2 = 4(x + 1)\) is in the standard form of a parabola that opens to the right. The standard form is \((y - k)^2 = 4p(x - h)\), where \((h, k)\) is the vertex and \(p\) is the distance from the vertex to the focus. 2. **Find the Vertex and Focus**: From the equation, we can identify: - Vertex \((h, k) = (-1, 2)\) - The value of \(4p = 4\), thus \(p = 1\). - The focus is located at \((h + p, k) = (-1 + 1, 2) = (0, 2)\). 3. **Equation of the Line**: A line passing through the focus \((0, 2)\) can be expressed in slope-intercept form as: \[ y - 2 = m(x - 0) \implies y = mx + 2 \] 4. **Set Up the Intersection**: To find the points of intersection between the line and the parabola, we substitute \(y = mx + 2\) into the parabola's equation: \[ (mx + 2 - 2)^2 = 4(x + 1) \] Simplifying this gives: \[ (mx)^2 = 4(x + 1) \implies m^2x^2 = 4x + 4 \] Rearranging leads to: \[ m^2x^2 - 4x - 4 = 0 \] 5. **Determine Conditions for Two Distinct Intersections**: For the quadratic equation \(m^2x^2 - 4x - 4 = 0\) to have two distinct solutions, the discriminant must be greater than zero: \[ D = b^2 - 4ac = (-4)^2 - 4(m^2)(-4) = 16 + 16m^2 \] Setting the discriminant greater than zero: \[ 16 + 16m^2 > 0 \] This inequality is always true for all real values of \(m\). 6. **Special Case for Horizontal Line**: The only exception occurs when \(m = 0\) (the horizontal line \(y = 2\)), which intersects the parabola at exactly one point. Therefore, \(m = 0\) must be excluded from the range. 7. **Conclusion**: The range of slopes \(m\) for which the line intersects the parabola at two distinct points is: \[ m \in (-\infty, 0) \cup (0, \infty) \]
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OBJECTIVE RD SHARMA ENGLISH-PARABOLA-Exercise
  1. f the normal at the point P (at1, 2at1) meets the parabola y^2=4ax agu...

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  2. The equation of the parabola whose vertex is at(2, -1) and focus at(2,...

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  3. The ends of a line segment are P(1, 3) and Q(1,1), R is a point on th...

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  4. The vertex of the parabola y^2+6x-2y+13=0 is

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  5. The Cartesian equation of the directrix of the parabola whose parametr...

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  6. If the vertex of a parabola is (0, 2) and the extremities of latusrect...

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  7. A line L passing through the focus of the parabola (y-2)^(2)=4(x+1) in...

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  8. Let y=f(x) be a parabola, having its axis parallel to the y-axis, whic...

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  9. If two tangents drawn from the point (alpha,beta) to the parabola y^2=...

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  10. The angle between the tangents drawn form the point (3, 4) to the para...

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  11. set of values of m for which a chord of slope m of the circle x^2 + y^...

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  12. The mid-point of the line joining the common points of the line 2x-3y+...

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  13. Tangents PQ and PR are drawn to the parabola y^(2) = 20(x+5) and y^(2)...

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  14. PC is the normal at P to the parabola y^(2) = 4ax, C being on the axis...

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  15. From a fixed point A three normals are drawn to the parabola y^(2)=4ax...

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  16. The tangent to the parabola y=x^2 has been drawn so that the abscissa ...

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  17. A circle drawn on any focal AB of the parabola y^(2)=4ax as diameter c...

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  18. Let F be the focus of the parabola y^(2)=4ax and M be the foot of perp...

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  19. The focus of a parabola is (0, 0) and vertex (1, 1). If two mutually p...

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  20. The point P on the parabola y^(2)=4ax for which | PR-PQ | is maximum, ...

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