Here's the question you clicked on:
ElleCullen
sin(a - b) = sina cosb + cosa sinb for all values of a and b. True or false?
false, because the rules for sine a+b identities are. \[\sin(a +b) = \sin(a) ~\cos(b) + \cos(a) ~\sin(b)\]\[\sin(a -b) = \sin(a) ~\cos(b) - \cos(a) ~\sin(b)\]
you have two of them mixed, and two sides are for sure not always equal.
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