If A = 30°; show that : 1 + sin 2 A + cos 2 A/sin A + cos A = 2 cos A

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If A = 30°; show that :
cos 2A = cos⁴ A - sin⁴ A

If A = 30°; show that :
4 cos A cos (60° - A). cos (60° + A) = cos 3A