Prove sin4A=4sinA cos³A-4cosA sin³A
Answers
Answered by
5
sin(A+A+A+A)= sin4A = sin(A+A)cos(A+A)+cos(A+A)sin(A+A).
=> sin2Acos2A+cos2Asin2A.
=> 2sinAcosA(cos²A-sin²A)*2
=> 4sinAcos³A-4sin³AcosA
hence proved.
=> sin2Acos2A+cos2Asin2A.
=> 2sinAcosA(cos²A-sin²A)*2
=> 4sinAcos³A-4sin³AcosA
hence proved.
Similar questions
English,
8 months ago
Chemistry,
8 months ago
Math,
8 months ago
Math,
1 year ago
Political Science,
1 year ago