verify that equation is an identity:
1. sin(A+π) = -sinA
2. tan(x+45) = (1 + tanx) / (1 - tanx)
+118608 verify that equation is an identity:
It depends on what you are allowed to use to verify it.... but..
1. sin(A+π) = -sinA
\(LHS=sin(A+\pi)\\ LHS=sinAcos\pi+cosAsin\pi \\ LHS=(sinA*-1)+(cosA*0)\\ LHS=-sinA\\ LHS=RHS\\ QED \)
2. tan(x+45) = (1 + tanx) / (1 - tanx)
\(LHS\\ =tan(x+45)\\ =\frac{tanx+tan45}{1-tanxtan45}\\ =\frac{tanx+1}{1-tanx}\\ =\frac{1+tanx}{1-tanx}\\ =RHS\\ QED \)
