三角函数 sin sin0°=sin0=0sin15°=sin = ≈0.2588190451sin22.5°=sin = ≈0.3826834324sin30°=sin = =0.5sin45°=sin = ≈0.7071067812sin60°=sin = ≈0.8660254038sin67.5°=sin = ≈0.9238795325sin75°=sin = ≈0.9659258263sin90°=sin =1sin180°=sin =0sin270°=sin =-1sin360°=sin =0 cos cos0°=cos0=1cos15°=cos = ≈0.9659258263cos22.5°=cos = ≈0.9238795325cos30°=cos = ≈0.8660254038cos45°=cos = ≈嚷辣叠0.7071067812cos60°=cos = =0.5cos67.5°=cos = ≈0.3826834324cos75°=cos = ≈0.2588190451cos90°=cos =0cos180°=cos =-1cos270°=cos =0cos360°=cos =1 tan tan0°=tan0=0tan15°=tan = ≈0.2679491924tan22.5°=tan = ≈0.4142135624tan30°=tan = ≈0.5773502692tan45°=tan =1tan60°=tan = ≈1.7320508076tan67.5°=tan = ≈2.4142135624tan75°=tan = ≈3.7320508076tan135°=tan =-1tan180°=tan =0tan225°=tan =1tan315°=tan =-1tan360°=tan =0 特殊三角函数值表 α=0° sinα=0 cosα=1 tαnα=0 cotα→∞ secα=1 cscα→∞α=15°(π/12) sinα=(√6-√2)/4 cosα=(√6+√2)/4 tαnα=2-√3 cotα=2+√3 secα=√轿主料应欠良誉6-√2 cscα=√6+√2α=22.5°(π/8) sinα=√(2-√2)/2 cosα=√(2+√2)/2 tαnα=√2-1 cotα=√2+1 secα=√(4-2√2) cscα=√(4