Question

sin(a - b) = sina cosb + cosa sinb for all values of a and b. True or false?

Answer 1

false, because the rules for sine a+b identities are.

\[\sin(a +b) = \sin(a) ~\cos(b) + \cos(a) ~\sin(b)\]\[\sin(a -b) = \sin(a) ~\cos(b) - \cos(a) ~\sin(b)\]

Answer 2

you have two of them mixed, and two sides are for sure not always equal.

Answer 3

Thank you :)

Answer 4

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