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Let (α,0,β)(\alpha, 0, \beta) be the coordinates of the point, which divides the line segment joining the points (1,2,-3) and (1,-1,-4) internally, then (α2+β2)(\alpha^2+\beta^2) equals:

Solution

✅ Correct Option: 1

Let the ratio be k:1k:1. The yy-coordinate gives −k+2k+1=0\dfrac{-k+2}{k+1} = 0, so k=2k=2.

Then α=2(1)+1(1)3=1\alpha = \dfrac{2(1)+1(1)}{3} = 1 and β=2(−4)+1(−3)3=−113\beta = \dfrac{2(-4)+1(-3)}{3} = -\dfrac{11}{3}.

So α2+β2=1+1219=1309\alpha^2+\beta^2 = 1 + \dfrac{121}{9} = \dfrac{130}{9}.

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