Question

If a = 2i - j + k and b = i - 3j - 5k, then find |a × b|.

Answer 1

a=2i-j+k

b=i-3j-k

its ans is

axb=4i+3j-5k

than

|axb|=^4x4+3x3+(-5x--5)

=^16+9+25

=^50

Answer 2

Answer:

$\sqrt{210}$

Step-by-step explanation:

From above picture,

i(5+3)-j(-10-1)+k(-6+1)

= 8i+11j-5k

that implies |axb|=

$\sqrt{ {8}^{2} } + \sqrt{11 {}^{2} } + \sqrt{ - 5 {}^{2} }$

= root of √64+121+25

= √210.

•

• • |axb| = √210.

HOPE IT HELPS..!!