Which of these expressions is the simplified form of the expression (startfraction sine (x) over 1 minus cosine squared (x) endfraction) tangent (startfraction x over 2 endfraction) ? startfraction 1 minus cosine (x) over sine squared (x) endfraction startfraction 1 over 1 minus cosine (x) endfraction startfraction 1 over 1 cosine (x) endfraction startfraction 1 over 2 cosine (x) endfraction