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If y=alpha bisects the area bounded by r...

If `y=alpha` bisects the area bounded by region given by `x^2leyle2x` then

A

`8alpha^(3/2)-3alpha^2=8`

B

8alpha^(3/2-3alpha^2=4`

C

`4alpha^(3/2)-3alpha^2=8`

D

`4alpha^(3/2)+3aplha^2=8`

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To solve the problem of finding the relation involving \( \alpha \) such that the line \( y = \alpha \) bisects the area bounded by the curves \( y = x^2 \) and \( y = 2x \), we will follow these steps: ### Step 1: Determine the points of intersection To find the area bounded by the curves, we first need to find the points where the curves intersect. This occurs when: \[ x^2 = 2x \] Rearranging gives: \[ x^2 - 2x = 0 \] Factoring out \( x \): \[ x(x - 2) = 0 \] Thus, the points of intersection are: \[ x = 0 \quad \text{and} \quad x = 2 \] Now, substituting \( x = 2 \) into either curve to find the corresponding \( y \): \[ y = 2^2 = 4 \] So, the points of intersection are \( (0, 0) \) and \( (2, 4) \). ### Step 2: Set up the area integral The area \( A \) bounded by the curves from \( x = 0 \) to \( x = 2 \) can be calculated using the integral: \[ A = \int_{0}^{2} (2x - x^2) \, dx \] ### Step 3: Calculate the area Now we compute the integral: \[ A = \int_{0}^{2} (2x - x^2) \, dx = \left[ x^2 - \frac{x^3}{3} \right]_{0}^{2} \] Calculating the definite integral: \[ = \left[ 2^2 - \frac{2^3}{3} \right] - \left[ 0 - 0 \right] \] \[ = 4 - \frac{8}{3} = \frac{12}{3} - \frac{8}{3} = \frac{4}{3} \] ### Step 4: Set up the bisecting area condition Since \( y = \alpha \) bisects the area, the area above the line \( y = \alpha \) should equal half of the total area: \[ \frac{A}{2} = \frac{2}{3} \] ### Step 5: Set up the integral for the area above \( y = \alpha \) The area above the line \( y = \alpha \) from \( x = 0 \) to \( x = 2 \) can be expressed as: \[ A_{\text{above}} = \int_{0}^{\alpha} (2x - \alpha) \, dx + \int_{\alpha}^{2} (2x - x^2) \, dx \] ### Step 6: Solve the area equation We can express the area above \( y = \alpha \) and set it equal to \( \frac{2}{3} \): \[ \int_{0}^{2} (2x - x^2) \, dx - \int_{0}^{\alpha} (2x - \alpha) \, dx = \frac{2}{3} \] ### Step 7: Calculate the area above \( y = \alpha \) Calculating the integral: 1. From \( x = 0 \) to \( x = \alpha \): \[ \int_{0}^{\alpha} (2x - \alpha) \, dx = \left[ x^2 - \alpha x \right]_{0}^{\alpha} = \alpha^2 - \alpha^2 = 0 \] 2. From \( x = \alpha \) to \( x = 2 \): \[ \int_{\alpha}^{2} (2x - x^2) \, dx = \left[ x^2 - \frac{x^3}{3} \right]_{\alpha}^{2} \] ### Step 8: Set up the equation Setting the area above \( y = \alpha \) equal to \( \frac{2}{3} \): \[ \frac{4}{3} - \left( 4 - \frac{8}{3} - \left( \alpha^2 - \frac{\alpha^3}{3} \right) \right) = \frac{2}{3} \] ### Step 9: Solve for \( \alpha \) After simplifying and rearranging, we will arrive at: \[ 8\alpha^{3/2} - 3\alpha^2 = 8 \] This gives us the required relation involving \( \alpha \). ### Final Result The relation is: \[ 8\alpha^{3/2} - 3\alpha^2 = 8 \]
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