## ElleCullen Group Title sin(a - b) = sina cosb + cosa sinb for all values of a and b. True or false? 7 months ago 7 months ago

1. student_basil

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)$

2. student_basil

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

3. ElleCullen

Thank you :)

4. student_basil

$$\normalsize\color{black}{ \bf You}$$ $$\normalsize\color{black}{ \bf welcome~!}$$