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The tangents and normals are drawn at th...

The tangents and normals are drawn at the extremites of the latusrectum of the parabola `y^2=4x`. The area of quadrilateral so formed is `lamda`sq units, the value of `lamda` is

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To solve the problem, we need to find the area of the quadrilateral formed by the tangents and normals at the extremities of the latus rectum of the parabola \(y^2 = 4x\). ### Step-by-Step Solution: 1. **Identify the Latus Rectum Points**: The latus rectum of the parabola \(y^2 = 4x\) is vertical and passes through the focus of the parabola. The focus is at \((1, 0)\) and the endpoints of the latus rectum are \((1, 2)\) and \((1, -2)\). Thus, the points are: - \(A(1, 2)\) - \(D(1, -2)\) 2. **Find the Tangent at Point A**: The slope of the tangent at point \(A(1, 2)\) can be derived using the derivative of the parabola: \[ \frac{dy}{dx} = \frac{4}{2y} = \frac{4}{4} = 1 \] The equation of the tangent line at point \(A\) is: \[ y - 2 = 1(x - 1) \implies y = x + 1 \] The tangent line intersects the x-axis at point \(B\): \[ 0 = x + 1 \implies x = -1 \implies B(-1, 0) \] 3. **Find the Normal at Point A**: The slope of the normal is the negative reciprocal of the tangent slope: \[ m = -1 \] The equation of the normal line at point \(A\) is: \[ y - 2 = -1(x - 1) \implies y = -x + 3 \] The normal line intersects the x-axis at point \(C\): \[ 0 = -x + 3 \implies x = 3 \implies C(3, 0) \] 4. **Identify the Points**: We have the following points: - \(A(1, 2)\) - \(B(-1, 0)\) - \(C(3, 0)\) - \(D(1, -2)\) 5. **Calculate the Area of Quadrilateral ABCD**: We can use the formula for the area of a quadrilateral given its vertices: \[ \text{Area} = \frac{1}{2} \left| x_1y_2 + x_2y_3 + x_3y_4 + x_4y_1 - (y_1x_2 + y_2x_3 + y_3x_4 + y_4x_1) \right| \] Substituting the coordinates: \[ = \frac{1}{2} \left| 1\cdot0 + (-1)\cdot0 + 3\cdot(-2) + 1\cdot2 - (2\cdot(-1) + 0\cdot3 + 0\cdot1 + (-2)\cdot1) \right| \] Simplifying: \[ = \frac{1}{2} \left| 0 + 0 - 6 + 2 - (-2) \right| = \frac{1}{2} \left| -4 + 2 \right| = \frac{1}{2} \left| -4 \right| = \frac{1}{2} \cdot 4 = 8 \] Thus, the area of the quadrilateral ABCD is \(8\) square units, so \(\lambda = 8\). ### Final Answer: \[ \lambda = 8 \]
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