If b = 5.7 which equation is true? a - 3+b= 6 b- b-2= 5.5 c- b+4.4= 9.1 d- 6-b= 0.3

Which sum or difference identity would you use to verify that cos (180° - q) = -cos q? a.) sin (a -b) = sin a cos b – cos a sin b b.) cos (a -b) = cos a cos b – sin a sin b c.) cos (a -b) = cos a cosb + sin a sin b d.) sin (a + b) = sin a cos b + cos a sin b