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Byju's Answer
Standard X
Mathematics
Trigonometric Identities
Let A, B, C...
Question
Let
A
,
B
,
C
be the three angles such that
A
+
B
+
C
=
π
. If
tan
A
.
tan
B
=
2
. Then find the value of
cos
A
cos
B
cos
C
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Solution
Given,
tan
A
.
tan
B
=
2
Let
y
=
cos
A
cos
B
cos
C
=
cos
A
cos
B
cos
(
A
+
B
)
=
cos
A
cos
B
sin
A
sin
B
−
cos
A
cos
B
=
1
tan
A
tan
B
−
1
=
1
2
−
1
=
1
Ans: 1
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Q.
Let
A
,
B
,
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Q.
Let
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Let A,B,C be three angles such that
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Q.
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+
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Q.
Let
→
a
=
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^
i
+
^
j
−
2
^
k
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=
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j
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If
→
c
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a
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