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Byju's Answer
Standard XII
Mathematics
Fundamental Theorem In 3D
Find directio...
Question
Find direction ratio and the direction cosines of the vector
→
r
=
^
i
+
^
j
+
^
k
.
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Solution
Let
→
r
=
ˆ
i
+
ˆ
j
+
ˆ
k
=
1
ˆ
i
+
1
ˆ
j
+
1
ˆ
k
Direction ratios are
a=1, b=1, c=1
Magnitude of
→
r
=
√
1
2
+
1
2
+
1
2
∣
∣
→
r
∣
∣
=
√
3
Direction cosines are
⎛
⎜
⎝
a
∣
∣
→
a
∣
∣
,
b
∣
∣
→
a
∣
∣
,
c
∣
∣
→
a
∣
∣
⎞
⎟
⎠
Direction cosines of
→
a
=
(
1
√
3
,
1
√
3
,
1
√
3
)
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2
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Q.
Find direction angles and direction cosines of the following vectors :
^
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Q.
The direction cosines of
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Find the direction angles and direction cosines of the following vectors:
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Q.
If
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and
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