Answer:
The cross product is 47 i - 61 j + 17 k.
Step-by-step explanation:
Given that-
a = < -1, -3, -8 > , b = < 7, 4, -5 >
The cross product is
a × b =[tex]\left[\begin{array}{ccc}i&j&k\\-1&-3&-8\\7&4&-5\end{array}\right][/tex]
= i ( - 3 × -5 - 4 × -8 ) - j ( -1 × -5 - (-8) × 7 ) + k ( -1 × 4 - 7 × -3 )
= i ( 15 + 32 ) -j ×( 5 + 56 ) + k ( -4 + 21 )
= i ( 47) - j (61 ) + k (17)
= 47 i -61 j + 17 k
As we know that if two vectors A & B are perpendicular then
A . B = 0
So here only the given vector b = < 7,4, -5> is perpendicular to the resulting vector .
