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Prove that

0 votes

sin2a*cosa+cos2a*sina=sin3a?

plz explain ur steps

asked Jul 11, 2014 in PRECALCULUS by anonymous

1 Answer

0 votes

LHS = sin(2a) * cos(a) + cos(2a) * sin(a)

= sin(2a + a)                                      [Since sin(a + b) = sin(a)cos(b) + cos(a)sin(b)]

= sin(3a)

=RHS

Therefore sin(2a) * cos(a) + cos(2a) * sin(a) = sin(3a)

answered Jul 11, 2014 by joly Scholar

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