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Let A(alpha, 1/(alpha)),B(beta,1/(beta))...

Let `A(alpha, 1/(alpha)),B(beta,1/(beta)),C(gamma,1/(gamma))` be the vertices of a `DeltaABC` where `alpha, beta` are the roots of the equation
`x^(2)-6p_(1)x+2=0, beta, gamma` are the roots of the equation
`x^(2)-6p_(2)x+3=0` and `gamma, alpha` are the roots of the equation
`x^(2)-6p_(3)x+6=0, p_(1),p_(2),p_(3)` being positive. Then the coordinates of the cenroid of `DeltaABC` is

A

`(1,11/18)`

B

`(0,11/8)`

C

`(2,11/18)`

D

None of these

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To find the coordinates of the centroid of triangle ABC with vertices at points A(α, 1/α), B(β, 1/β), and C(γ, 1/γ), we will follow these steps: ### Step 1: Find the roots α and β from the first equation The first equation is given as: \[ x^2 - 6p_1x + 2 = 0 \] Using Vieta's formulas, we know: - The sum of the roots (α + β) = 6p_1 - The product of the roots (αβ) = 2 ### Step 2: Find the roots β and γ from the second equation The second equation is given as: \[ x^2 - 6p_2x + 3 = 0 \] Using Vieta's formulas again: - The sum of the roots (β + γ) = 6p_2 - The product of the roots (βγ) = 3 ### Step 3: Find the roots γ and α from the third equation The third equation is given as: \[ x^2 - 6p_3x + 6 = 0 \] Using Vieta's formulas: - The sum of the roots (γ + α) = 6p_3 - The product of the roots (γα) = 6 ### Step 4: Multiply the three equations From the three sets of equations, we can multiply the products of the roots: \[ (αβ)(βγ)(γα) = 2 \cdot 3 \cdot 6 \] This gives us: \[ (αβγ)^2 = 36 \implies αβγ = 6 \] ### Step 5: Express α, β, and γ in terms of p_1, p_2, and p_3 Now we can express α, β, and γ using the products: - From αβ = 2, we can express β as \( β = \frac{2}{α} \). - From βγ = 3, we can express γ as \( γ = \frac{3}{β} = \frac{3α}{2} \). - From γα = 6, we can express α as \( α = \frac{6}{γ} = \frac{6 \cdot 2}{3} = 4 \). ### Step 6: Substitute to find β and γ Using α = 4: - \( β = \frac{2}{4} = \frac{1}{2} \) - \( γ = \frac{3}{\frac{1}{2}} = 6 \) ### Step 7: Find the coordinates of the centroid The coordinates of the centroid (G) of triangle ABC can be calculated using the formula: \[ G\left(\frac{x_1 + x_2 + x_3}{3}, \frac{y_1 + y_2 + y_3}{3}\right) \] Substituting the coordinates: - \( x_1 = α = 4 \) - \( x_2 = β = \frac{1}{2} \) - \( x_3 = γ = 6 \) Calculating the x-coordinate of the centroid: \[ G_x = \frac{4 + \frac{1}{2} + 6}{3} = \frac{10.5}{3} = 3.5 \] Calculating the y-coordinates: - \( y_1 = \frac{1}{α} = \frac{1}{4} \) - \( y_2 = \frac{1}{β} = 2 \) - \( y_3 = \frac{1}{γ} = \frac{1}{6} \) Calculating the y-coordinate of the centroid: \[ G_y = \frac{\frac{1}{4} + 2 + \frac{1}{6}}{3} = \frac{\frac{3}{12} + \frac{24}{12} + \frac{2}{12}}{3} = \frac{\frac{29}{12}}{3} = \frac{29}{36} \] ### Final Coordinates of the Centroid Thus, the coordinates of the centroid G are: \[ G\left(3.5, \frac{29}{36}\right) \]
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Knowledge Check

  • If A(alpha, (1)/(alpha)), B(beta, (1)/(beta)), C(gamma,(1)/(gamma)) be the vertices of a Delta ABC , where alpha, beta are the roots of x^(2)-6ax+2=0, beta, gamma are the roots of x^(2)-6bx+3=0 and gamma, alpha are the roots of x^(2)-6cx + 6 =0 , a, b, c being positive. The value of a+b+c is

    A
    1
    B
    2
    C
    3
    D
    5
  • If A(alpha, (1)/(alpha)), B(beta, (1)/(beta)), C(gamma,(1)/(gamma)) be the vertices of a Delta ABC , where alpha, beta are the roots of x^(2)-6ax+2=0, beta, gamma are the roots of x^(2)-6bx+3=0 and gamma, alpha are the roots of x^(2)-6cx + 6 =0 , a, b, c being positive. The coordinates of orthocentre of Delta ABC is

    A
    `(-(1)/(2),-2)`
    B
    `(-(1)/(3),-3)`
    C
    `(-(1)/(5),-5)`
    D
    `(-(1)/(6),-6)`
  • If A(alpha, (1)/(alpha)), B(beta, (1)/(beta)), C(gamma,(1)/(gamma)) be the vertices of a Delta ABC , where alpha, beta are the roots of x^(2)-6ax+2=0, beta, gamma are the roots of x^(2)-6bx+3=0 and gamma, alpha are the roots of x^(2)-6cx + 6 =0 , a, b, c being positive. The coordinates of centroid of Delta ABC is

    A
    `(1,(11)/(9))`
    B
    `((1)/(3),(11)/(18))`
    C
    `(2,(11)/(18))`
    D
    `((2)/(3),(11)/(19))`
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