三角函数值（附三角函数值表）（1）特殊角三角函数值sin0=0sin30=0.5sin45=0.7071二分之根号2sin60=0.8660二分之根号3sin90=1cos0=1cos30=0.866025404二分之根号3cos45=0.707106781二分之根号2cos60=0.5cos90=0tan0=0tan30=0.577350269三分之根号3tan45=1tan60=1.732050808根号3tan90=无cotO=无cot30=1.732050808根号3cot45=1cot60=0.577350269三分之根号3cot90=0(2)090的任意角的三角函数值，查三角函数表。(见下)(3)锐角三角函数值的变化情况(i)锐角三角函数值都是正值（ii）当角度在0。90。间变化时，正弦值随着角度的增大（或减小）而增大（或减小）余弦值随着角度的增大（或减小）而减小（或增大）正切值随着角度的增大（或减小）而增大（或减小）余切值随着角度的增大（或减小）而减小（或增大）(iii)当角度在0七a90。间变化时，0sinacosa0,当角度在0a0,cota0.“锐角三角函数”属于三角学，是数学课程标准中“空间与图形”领域的重要内容。从数学课程标准看，中学数学把三角学内容分成两个部分，第一部分放在义务教育第三学段，第二部分放在高中阶段。在义务教育第三学段，主要研究锐角三角函数和解直角三角形的内容，附：三角函数值表sin0=0,sin15=(76-P)/4,sin30=1/2sin45=72/2,sin60=73/2,sin75=(76+72)/2,sin90=1,sin105=72/2*(73/2+1/2)sin120=73/2sin135=72/2sin150=1/2sin165=(76-72)/4sin180=0sin270=-1sin360=0sin1=0.01745240643728351sin2=0.03489949670250097sin3=0.05233595624294383sin4=0.0697564737441253sin5=0.08715574274765816sin6=0.10452846326765346sin7=0.12186934340514747sin8=0.13917310096006544sin9=0.15643446504023087sin10=0.17364817766693033sin11=0.1908089953765448sin12=0.20791169081775931sin13=0.22495105434386497sin14=0.24192189559966773sin15=0.25881904510252074sin16=0.27563735581699916sin17=0.2923717047227367sin18=0.3090169943749474sin19=0.3255681544571567sin20=0.3420201433256687sin21=0.35836794954530027sin22=0.374606593415912sin23=0.3907311284892737sin24=0.40673664307580015sin25=0.42261826174069944sin26=0.4383711467890774sin27=0.45399049973954675sin28=0.4694715627858908sin29=0.48480962024633706sin30=0.49999999999999994sin31=0.5150380749100542sin32=0.5299192642332049sin33=0.544639035015027sin34=0.5591929034707468sin35=0.573576436351046sin36=0.5877852522924731sin37=0.6018150231520483sin38=0.6156614753256583sin39=0.6293203910498375sin40=0.6427876096865392sin41=0.6560590289905073sin42=0.6691306063588582sin43=0.6819983600624985sin44=0.6946583704589972sin45=0.7071067811865475sin46=0.7193398003386511sin47=0.7313537016191705sin48=0.7431448254773941sin49=0.7547095802227719sin50=0.766044443118978sin51=0.7771459614569708sin52=0.7880107536067219sin53=0.7986355100472928sin54=0.8090169943749474sin55=0.8191520442889918sin56=0.8290375725550417sin57=0.8386705679454239sin58=0.848048096156426sin59=0.8571673007021122sin60=0.8660254037844386sin61=0.8746197071393957sin62=0.8829475928589269sin63=0.8910065241883678sin64=0.898794046299167sin65=0.9063077870366499sin66=0.9135454576426009sin67=0.9205048534524404sin68=0.9271838545667873sin69=0.9335804264972017sin70=0.9396926207859083sin71=0.9455185755993167sin72=0.9510565162951535sin73=0.9563047559630354sin74=0.9612616959383189sin75=0.9659258262890683sin76=0.9702957262759965sin77=0.9743700647852352sin78=0.9781476007338057sin79=0.981627183447664sin80=0.984807753012208sin81=0.9876883405951378sin82=0.9902680687415704sin83=0.992546151641322sin84=0.9945218953682733sin85=0.9961946980917455sin86=0.9975640502598242sin87=0.9986295347545738sin88=0.9993908270190958sin89=0.9998476951563913sin90=1cos1=0.9998476951563913cos2=0.9993908270190958cos3=0.9986295347545738cos4=0.9975640502598242cos5=0.9961946980917455cos6=0.9945218953682733cos7=0.992546151641322cos8=0.9902680687415704cos9=0.9876883405951378cos10=0.984807753012208cos11=0.981627183447664cos12=0.9781476007338057cos13=0.9743700647852352cos14=0.9702957262759965cos15=0.9659258262890683cos16=0.9612616959383189cos17=0.9563047559630355cos18=0.9510565162951535cos19=0.9455185755993168cos20=0.9396926207859084cos21=0.9335804264972017cos22=0.9271838545667874cos23=0.9205048534524404cos24=0.9135454576426009cos25=0.9063077870366499cos26=0.898794046299167cos27=0.8910065241883679cos28=0.882947592858927cos29=0.8746197071393957cos30=0.8660254037844387cos31=0.8571673007021123cos32=0.848048096156426cos33=0.838670567945424cos34=0.8290375725550417cos35=0.8191520442889918cos36=0.8090169943749474cos37=0.7986355100472928cos38=0.7880107536067219cos39=0.7771459614569709cos40=0.766044443118978cos41=0.754709580222772cos42=0.7431448254773942cos43=0.7313537016191705cos44=0.7193398003386512cos45=0.7071067811865476cos46=0.6946583704589974cos47=0.6819983600624985cos48=0.6691306063588582cos49=0.6560590289905074cos50=0.6427876096865394cos51=0.6293203910498375cos52=0.6156614753256583cos53=0.6018150231520484cos54=0.5877852522924731cos55=0.5735764363510462cos56=0.5591929034707468cos57=0.5446390350150272cos58=0.5299192642332049cos59=0.5150380749100544cos