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Question
Mathematics
If cos h-1 x = 2 loge ( √2 + 1 ), then x =
Q. If
cos
h
−
1
x
=
2
lo
g
e
(
2
+
1
)
, then x =
1935
260
TS EAMCET 2017
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A
1
50%
B
2
50%
C
4
0%
D
3
0%
Solution:
We have,
cosh
−
1
x
=
2
lo
g
θ
(
2
+
1
)
⇒
lo
g
e
(
x
+
x
2
−
1
)
=
lo
g
e
(
2
+
1
)
2
⇒
x
+
x
2
−
1
=
(
2
+
1
)
2
⇒
x
+
x
2
−
1
=
3
+
2
2
=
3
+
8
On comparing rational and irrational part, we get
x
=
3