関連ワード:  is sec inverse equal to cos    is sec 1 equal to cos    is sec inverse equal to 1/ cos inverse    is 1 sec 2x equal to cos 2x    is 1 sec 2 equal to cos 2    is 1 sec x equal to cos x    is secant equal to cos 1    is sec equivalent to 1 cos    is cosine equal to 1/secant    sec inverse x is equal to cosec inverse y