sin2120°+cos180°+tan45°-cos2(-330°)+sin(-210°) 最好快点、、sin2120°+cos180°+tan45°-cos2(-330°)+sin(-210°)

sin2120°+cos180°+tan45°-cos2(-330°)+sin(-210°) 最好快点、、sin2120°+cos180°+tan45°-cos2(-330°)+sin(-210°) cos180°为什么等于-1呢? cos180°为什莫等于-1求详解～ 化简：-p²cos180°+qsin9°-2pqcos0°化简-p²cos180°+qsin9°-2pqcos0° sin1°+sin2°+...+sin89°+sin90°+cos91°+cos92°+...+cos179°+cos180° 求值sin120°+cos180°+tan45°-cos（-330°）+sin(-210°) 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? -p^2 cos180°+q^2 sin90°-2pq cos0°=? -p方cos180°+q方sin90°-2pqcos0° 化简-p平方cos180°+q平方sin90°-2pqcos0° 化简－α²cos180°+β²sin90°－2αβcos0° 高一三角函数计算如题 ①2sin0°+5sin90°-3sin270°+10sin180° ②sinπ/6-√2sinπ/4+4/3sinπ/3+sinπ/6+sin3π/2 ③cos0°+5sin90°-3sin270°+10cos180° ④cosπ/3-tanπ/4+3/4tanπ/6-sinπ/6+cosπ/6+sin3π/2 ⑤sin四次方π/4-cosπ/2+6tan 请问：sin0°= sin90°=?sin180° cos0°= cos90°=?cos180° tan0°= tan90°=?tan180° 顺便再问下cos310°tan（-108°）是什么意思？这两个三角函数中间没有乘号，意思和有乘号的有什么区别