関連ワード:  is secant equal to cos^-1    is secant equal to cos 1    is sec equal to cos 1    is cosine equal to 1/secant    is sec equivalent to 1 cos    is sec equal to cos inverse    is secant squared equal to 1/cos squared    is sec 2x equal to 1 cos 2x    is sec 2 equal to 1 cos 2    is sec squared equal to 1 cos squared