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MATHEMATICS · Single correct · CBSE · Mathematics · Trigonometric Functions · Trigonometric Functions
Problem Which of the following identities holds true for all real x x x y y y cos ( x + y ) = cos x cos y + sin x sin y \cos(x+y)=\cos x\cos y+\sin x\sin y cos ( x + y ) = cos x cos y + sin x sin y sin ( x + y ) = sin x cos y − cos x sin y \sin(x+y)=\sin x\cos y-\cos x\sin y sin ( x + y ) = sin x cos y − cos x sin y cos ( x + y ) = cos x cos y − sin x sin y \cos(x+y)=\cos x\cos y-\sin x\sin y cos ( x + y ) = cos x cos y − sin x sin y sin ( x + y ) = sin x sin y + cos x cos y \sin(x+y)=\sin x\sin y+\cos x\cos y sin ( x + y ) = sin x sin y + cos x cos y Browse the problem library