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Problem
Problem
In a
Δ
A
B
C
\Delta ABC
Δ
A
B
C
, let
a
=
6
,
b
=
3
a = 6, b = 3
a
=
6
,
b
=
3
and
cos
(
A
−
B
)
=
4
5
\cos(A - B) = \frac{4}{5}
cos
(
A
−
B
)
=
5
4
. [Note All symbols used have usual meaning in a triangle.] a. Statement I
∠
B
=
π
2
\angle B = \frac{\pi}{2}
∠
B
=
2
π
b. Statement II
sin
A
=
2
5
\sin A = \frac{2}{\sqrt{5}}
sin
A
=
5
2
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