Sin(A+B) = SinACosB + CosASinB
Cos(A+B) = CosACosB - SinASinB
Note pi is taken as pi radians = 180 degrees. Cospi = Cos180 = -1.
Sinpi = Sin 180 = 0
Cos(A+pi) = CosACospi - SinASinpi = (CosA) * (-1) - (SinA) *(0) = -CosA.
Sin(A+pi) = SinACospi + CosASinpi = (SinA)* (-1) + (CosA) * (0) = -SinA.
Cos(A+pi) - Sin(A+pi) = -CosA - -SinA = -CosA + SinA = SinA - CosA.
Answer = (a).
Answer:
The missing justification is the transitive property.
Step-by-step explanation:
The missing justification is the transitive property. The transitive property states that: If a = b and b = c, then a = c.
