Aký je krížový produkt [9,4, -1] a [-1, -1, 2]?

odpoveď:

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

vysvetlenie:

# A = a_i, a_j, a_k #

# B = b_i, b_j, b_k #

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

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