If the points `(-1,1,2),(2,m ,5)a n d(3,11 ,6)` are collinear, find the value of `mdot`

Explanation

Let the given points be
`A(−1,−1,2),B(2,m,5),C(3,11,6)`.

Then, `AB=(2+1)i+(m+1)j
​+(5−2)k`

`=3i+(m+1)j​+3k`

and, `AC=(3+1)i+(11+1)j+(6−2)k`

`=4i+12j+4k`

Now, `AB=λAC`

`3i+(m+1)j+3k`

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