If $A = < 4, 9, - 1 >$ $A= <4, 9 ,-1 >$ and $B = < 9, - 1, 8 >$ $B= <9 ,-1 ,8 >$ , what is $A \cdot B - | | A | | | | B | |$ $A*B -||A|| ||B||$ ?

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If $A = < 4, 9, - 1 >$ $A= <4, 9 ,-1 >$ and $B = < 9, - 1, 8 >$ $B= <9 ,-1 ,8 >$ , what is $A \cdot B - | | A | | | | B | |$ $A*B -||A|| ||B||$ ?

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Answer 1 · 2016-10-20T18:41:37

The answer is $19 - \sqrt{98} \cdot \sqrt{146} =$ $19-sqrt98*sqrt146=$

Explanation:

The dot product is $\to A . \to B = 36 - 9 - 8 = 19$ $vecA.vecB=36-9-8=19$
Norm of $∥ ∥ ∥ \to A ∥ = \sqrt{16 + 81 + 1} = \sqrt{98}$ $∥vecA∥=sqrt(16+81+1)=sqrt(98)$
Norm of $∥ ∥ ∥ \to B ∥ = \sqrt{81 + 1 + 64} = \sqrt{146}$ $∥vecB∥=sqrt(81+1+64)=sqrt(146)$
So the result is $= \to A . \to B - ∥ \to A ∥ \cdot ∥ \to B ∥ = 19 - \sqrt{98} \cdot \sqrt{146}$ $=vecA.vecB-∥vecA∥*∥vecB∥=19-sqrt98*sqrt146$

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If $A = < 4, 9, - 1 >$ $A= <4, 9 ,-1 >$ and $B = < 9, - 1, 8 >$ $B= <9 ,-1 ,8 >$ , what is $A \cdot B - | | A | | | | B | |$ $A*B -||A|| ||B||$ ?

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If A=<4,9,−1>A= <4, 9 ,-1 > and B=<9,−1,8>B= <9 ,-1 ,8 >, what is A⋅B−||A||||B||A*B -||A|| ||B||?

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If $A = < 4, 9, - 1 >$ $A= <4, 9 ,-1 >$ and $B = < 9, - 1, 8 >$ $B= <9 ,-1 ,8 >$ , what is $A \cdot B - | | A | | | | B | |$ $A*B -||A|| ||B||$ ?