Let us assume that vectors are collinear so, AB∥AC if 21=−6α−4=21⇒α=1
Now, for a,b,c to be non-collinear smallest positive integer will be α=2
So, mid-point of BC=M(25,0,29)
Now, AM=49+16+49=282
JEE Main 2022 — Mathematics Vectors & 3D Geometry
Let A,B,C be three points whose position vectors respectively are:
a=i^+4j^+3k^
b=2i^+αj^+4k^,α∈R
c=3i^−2j^+5k^
If α is the smallest positive integer for which a,b,c are non-collinear, then the length of the median, △ABC, through A is:
Held on 29 Jun 2022 · Verified 6 Jul 2026.
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