Question

Find the scalar and vector products of two vectors a= 3i-4j+5k

and b =(-27 +3+33)​

Answer 1

Explanation:

a=3i-4j+5k b=-27i+3j+33k

scaler product

a.b=3×-27(i.i)-4×3(j.j)+5×5(k.k)

=-81-12+25

=-93+25

=-68

vector product

a×b=i j k

3 -4 5

-27 3 33

= ((-132)-(15))i-((99)-(135))j+((9)-(108))k

=-147i+36j-99k

Answer 2

Explanation:

⋅b=(3

i

^

−4

j

^

+5

k

^

)⋅(−2

i

^

+

j

^

−3

k

^

)

=−6−4−15

=−25

a×b=

∣

∣

∣

∣

∣

∣

∣

∣

i

^

3

−2

j

^

−4

1

k

^

5

−3

∣

∣

∣

∣

∣

∣

∣

∣

=7

i

^

−

j

^

−5

k

^

Note b×a=−7

i

^

+

j

^

+5

k

^