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Question
Mathematics
Let veca = hati - hatk , vecb = x hati + hatj + (1 - x) hatk and vecc = y hati + x hatj + ( 1 +x -y ) hatk . Then [ veca , vecb , vecc ] depends on
Q. Let
a
=
i
^
−
k
^
,
b
=
x
i
^
+
j
^
+
(
1
−
x
)
k
^
and
c
=
y
i
^
+
x
j
^
+
(
1
+
x
−
y
)
k
^
.
Then
[
a
,
b
,
c
]
depends on
1458
213
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A
only y
0%
B
only x
11%
C
both x and y
44%
D
neither x nor y
44%
Solution:
a
=
i
^
−
k
^
,
b
=
x
i
^
+
j
^
+
(
1
−
x
)
k
^
and
c
=
y
i
^
+
x
j
^
+
(
1
+
x
−
y
)
k
^
[
a
b
c
]
=
a
b
×
c
=
∣
∣
1
x
y
0
1
x
−
1
1
−
x
1
+
x
−
y
∣
∣
=
1
[
1
+
x
−
y
−
x
+
x
2
]
−
[
x
2
−
y
]
=
1
−
y
+
x
2
−
x
2
+
y
=
1
Hence
[
a
,
b
,
c
]
is independent of
x
and
y
both.