Mathematics - Vector Question with Solution | TestHub

MathematicsVectorSTPMedium2 minPYQ_2014
MathematicsMediumnumerical

Leta, bandcbe three non - coplanar unit vectors such that the angle between every pair of them isπ3.Ifa × b+ b × c=pa+qb+rc, where p, q and r are scalars, then the value ofp2+2q2+r2q2 is _______

Answer:
4.00
Solution:

a=b= c=1
a × b+ b × c=pa+qb+rc
a . b × c=p+q a . b+ra . c
Anda  b  c=12
p+q2+r2=a b c.......(i)
p2+q+r2=0......(ii)
p2+q2+r=a b c......(iii)
p=r= -q
p2+2q2+r2q2=4

Stream:JEE_ADVSubject:MathematicsTopic:VectorSubtopic:STP
2mℹ️ Source: PYQ_2014

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