高中三角函数公式大全(2)

高中三角函数公式大全

sina-sinb=2cosa b

2sina b2 cosa+cosb = 2coscosa-cosb = -2sin

tana+tanb=a b2a b2cossina b2a b2sin(a b)

cosacosb

1

2

1

2

1

2

1

2 积化和差 sinasinb = -cosacosb = sinacosb = cosasinb = [cos(a+b)-cos(a-b)] [cos(a+b)+cos(a-b)] [sin(a+b)+sin(a-b)] [sin(a+b)-sin(a-b)]

诱导公式

sin(-a) = -sina

cos(-a) = cosa sin(

cos(

sin(

cos( 2-a) = cosa -a) = sina +a) = cosa +a) = -sina 2 2

2

sin(π-a) = sina

cos(π-a) = -cosa

sin(π+a) = -sina

cos(π+a) = -cosa tgA=tanA =

万能公式 2tana

2

a

2

a

a

2sinacosa sina=1 (tan1 (tan )2))2cosa=1 (tan 2