求值sin120°+cos180°+tan45°-cos（-330°）+sin(-210°)

求值sin120°+cos180°+tan45°-cos（-330°）+sin(-210°) sin120°=? sin120°的值为 sin120°等于cos多少 sin120°、sin210°分别是多少? sin120°和sin60相等吗? cos180°为什么等于-1呢? 关于sin120°的值sin120°的值怎么理解（图也看不懂） cos180°为什莫等于-1求详解～ 化简：-p²cos180°+qsin9°-2pqcos0°化简-p²cos180°+qsin9°-2pqcos0° sin2120°+cos180°+tan45°-cos2(-330°)+sin(-210°) 最好快点、、sin2120°+cos180°+tan45°-cos2(-330°)+sin(-210°) sin1°+sin2°+...+sin89°+sin90°+cos91°+cos92°+...+cos179°+cos180° sin平方120°+cos180°+tan45°-cos平方(-330°)+sin(-210°) cos1°+cos2°+cos3°+……+cos179°+cos180°的值是( 计算3cos90°-2sin0°+tan0°-cos180°+tan180° cos1°+cos2°+cos3°+...+cos180°的值为?到底是0还是-1? cos1°+cos2°+cos3°+...+cos180°的值为? cos180°,sin180°,tan180°分别等于多少?怎样求得?