For 0 less-than x less-than startfraction pi over 2 endfraction, which expression is equivalent to startstartfraction sine (startfraction x over 2 endfraction) tangent (startfraction x over 2 endfraction) overover 1 minus cosine (x) endendfraction? startfraction 1 over startroot 2 (1 + cosine x) endroot endfraction startfraction 1 over startroot 2 (1 minus cosine x) endroot endfraction (startroot startfraction 1 + cosine (x) over 2 endfraction endroot) (startfraction 1 over 1 minus cosine (x) endfraction) (startfraction 1 + cosine (x) over startroot 2 (1 minus cosine x) endroot endfraction) (startfraction 1 over 1 minus cosine (x) endfraction).