関連ワード:  is cosine equal to 1/secant    is cos equal to 1 sec    is cos theta equal to 1 sec theta    is cos 2 equal to 1 sec 2    is secant equal to 1 over cosine    is inverse secant equal to cosine    is inverse cosine the same as secant    is secant the same as cos^-1    what is 1/secant