Apakah produk silang [9,4, -1] dan [-1, -1, 2]?

Apakah produk silang [9,4, -1] dan [-1, -1, 2]?
Anonim

Jawapan:

#A X B = 7i-17j-5k #

Penjelasan:

# A = a_i, a_j, a_k #

# B = b_i, b_j, b_k #

#A X B = i (a_j * b_k-a_k * b_j) -j (a_i * b_k-a_k * b_i) + k (a_i * b_j-a_j * b_i) #

#thus; #

# A = 9,4, -1 #

#B = - 1, -1,2 #

#A X B = i (4 * 2 - (- 1 * -1)) - j (9 * 2 - (- 1 * -1)) + k (-1 * 9-4 * -1)

#A X B = i (8-1) -j (18-1) + k (-9 + 4) #

#A X B = 7i-17j-5k #