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Mathematics
Mathematics
Problem
(a) State the identity that rewrites
sin
A
−
sin
B
\sin A-\sin B
sin
A
−
sin
B
as a product. (b) Using this identity, show that
sin
7
x
−
sin
5
x
=
2
cos
6
x
sin
x
\sin 7x-\sin 5x=2\cos 6x\sin x
sin
7
x
−
sin
5
x
=
2
cos
6
x
sin
x
.
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