Let a,b and c be three non-coplanar vectors, and let p,q and r be the vectors defined by the relation p=b×c[abc],q=c×a[abc], and r=a×b[abc], Then the value of the expression (a+b)⋅p+(b+c)⋅q+(c+a)⋅r is equal to
A
0
No worries! We‘ve got your back. Try BYJU‘S free classes today!
B
1
No worries! We‘ve got your back. Try BYJU‘S free classes today!
C
2
No worries! We‘ve got your back. Try BYJU‘S free classes today!
D
3
Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses
Open in App
Solution
The correct option is D3 a⋅p=a⋅(b×c)[abc]=[abc][abc]=1 b⋅p=b⋅(b×c)[abc]=0[abc]=0 b⋅q=b⋅(c×a)[abc]=(b×c)⋅a[abc]a⋅(b×c)[abc][abc][abc]=1 c⋅q=c⋅(c×a)[abc]=0 c⋅r=(a×b)⋅c[abc]=1 and a⋅r=0 Therefore, the given expression is equal to 1+0+1+0+1+0=3.