If sinA +sin (2)^A=1 Prove that cos (2)^A+cos (4)^A=1

1.	If sinA +sin (2)^A=1 Prove that cos (2)^A+cos (4)^A=1
Answer» {tex}SinA + Sin\\ ^ 2A = 1{/tex}{tex}SinA = 1-Sin\\ ^ 2A{/tex}{tex}SinA = Cos\\ ^ 2 A{/tex}( Using identity)Squaring both sides,{tex}(SinA)\\ ^ 2 = ( Cos\\ ^2 A )\\ ^ 2{/tex}{tex}Sin\\ ^ 2 A=Cos\\ ^ 4 A{/tex}{tex}1- Cos\\ ^ 2 A= Cos \\ ^ 4 A{/tex}( Using identity){tex}1 = Cos \\ ^ 2A + Cos \\ ^ 4 A{/tex}{tex}Cos \\ ^ 2A + Cos \\ ^ 4 A = 1{/tex}

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