初中三角函数值表

初中三角函数值表

特殊角三角函数值

sin0=0 sin30=0.5 sin45=0.7071=22 sin60=23

=0.866 sin90=1 cos0=1 cos30=23=0.866 cos45=22

=0.70 cos60=0.5 cos90=0 tan0=0 tan30=33

=0.577 tan45=1

tan60=3=1.732 tan90=无 cot0=无cot30=3=1.732 cot45=1

cot60=33

=0.577 cot90=0

（2）0°～90°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°≤α≤90°间变化时，

0≤sinα≤1, 1≥cosα≥0,

当角度在0°<α<90°间变化时，

tanα>0, cotα>0.

附：三角函数值表

sin0=0,

sin15=（√6-√2)/4 ,

sin30=1/2,

sin45=√2/2,

sin60=√3/2,

sin75=(√6+√2)/2 ,

sin90=1,

sin105=√2/2*(√3/2+1/2)

sin120=√3/2

sin135=√2/2

sin150=1/2

sin165=（√6-√2)/4 sin180=0

sin270=-1

sin360=0

sin1=0.01745 sin2=0.034899 sin3=0.052335 sin4=0.069756

sin5=0.087155

sin6=0.104528sin7=0.121869

sin8=0.139173

sin9=0.156434

sin10=0.17364

sin11=0.19080

sin12=0.20791sin13=0.22495

sin14=0.24192

sin15=0.25881sin16=0.27563

sin17=0.29237

sin18=0.30901

sin19=0.32556

sin20=0.34202

sin21=0.35836sin22=0.37460

sin23=0.39073

sin24=0.40673sin25=0.42261

sin26=0.43837 sin27=0.45399sin28=0.46947 sin29=0.48480 sin30=0.49999

sin31=0.51503

sin32=0.52991

sin33=0.54463sin34=0.55919

sin35=0.57357

sin36=0.58778sin37=0.60181

sin38=0.61566

sin39=0.62932

sin40=0.64278

sin41=0.65605

sin42=0.66913sin43=0.68199

sin44=0.69465

sin45=0.70710sin46=0.71933 sin47=0.73135

sin48=0.74314sin49=0.75470

sin50=0.76604

sin51=0.77714sin52=0.78801

sin53=0.79863

sin54=0.80901

sin55=0.81915

sin56=0.82903

sin57=0.83867

sin58=0.84804

sin59=0.85716

sin60=0.86602

sin61=0.87461

sin62=0.88294

sin63=0.89100sin64=0.89879 sin65=0.90630

sin66=0.91354sin67=0.92050 sin68=0.92718

sin69=0.93358

sin70=0.93969

sin71=0.94551

sin72=0.95105sin73=0.95630 sin74=0.96126

sin75=0.96592sin76=0.97029 sin77=0.97437

sin78=0.97814sin79=0.98162 sin80=0.98480

sin81=0.98768sin82=0.99026 sin83=0.99254

sin84=0.99452sin85=0.99619 sin86=0.99756

sin87=0.99862sin88=0.99939 sin89=0.99984

sin90=1

cos1=0.99984

cos2=0.99939

cos3=0.99862cos4=0.99756 cos5=0.99619

cos6=0.99452

cos7=0.99254

cos8=0.99026

cos9=0.98768cos10=0.9848

cos11=0.9816

cos12=0.97814cos13=0.9743