1. Find āxbl, if à =î - 7ị+ 7k and 5 = 3î - 2j+2.
Answers
Answer:
ok dobi
Step-by-step explanation:
Consider the vector
A
=2
i
^
+3
j
^
−4
k
^
And
B
=5
i
^
+2
j
^
+4
k
^
Now, as we know
A
.
B
=ABcosθ
θ is the angle between
A
and
B
Therefore,
cosθ=
AB
A
.
B
cosθ=
2
2
+3
2
+(−4)
2
5
2
+2
2
+4
2
(2
i
^
+3
j
^
−4
k
^
).(5
i
^
+2
j
^
+4
k
^
)
=
2
2
+3
2
+(−4)
2
5
2
+2
2
+4
2
(10+6−16)
=0
Therefore, cosθ=0
θ=90
∘
Hence angle between the vectors is 90
∘
Consider the vector
A
=2
i
^
+3
j
^
−4
k
^
And
B
=5
i
^
+2
j
^
+4
k
^
Now, as we know
A
.
B
=ABcosθ
θ is the angle between
A
and
B
Therefore,
cosθ=
AB
A
.
B
cosθ=
2
2
+3
2
+(−4)
2
5
2
+2
2
+4
2
(2
i
^
+3
j
^
−4
k
^
).(5
i
^
+2
j
^
+4
k
^
)
=
2
2
+3
2
+(−4)
2
5
2
+2
2
+4
2
(10+6−16)
=0
Therefore, cosθ=0
θ=90
∘
Hence angle between the vectors is 90
∘