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3 years ago

Sin(a+b) + sin (a-b) = 2 sin a cos b verify the identitiy

Mathematics

1 answer:

Bas_tet [7]3 years ago

6 0

Write out the sum formula for sin
<span>sin(x + y) = sinxcos + sinycosx </span>

<span>Then expand sin(a + b) + sin(a - b) </span>
<span>sinacosb + sinbcosa + sinacosb - sinbcosa </span>
<span>The 2nd and 4th terms cancel and you get </span>
<span>2sinacosb</span>

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