GoniometrickΘ funkcie

Vz╗ahy medzi funkciami
Funkcie s·Φtu a rozdielu
S·Φty a rozdiely funkciφ
S·Φiny funkciφ
Funkcie nßsobkov uhlov

Zßkladn² vz╗ah:

eia = cosa + isina

Vz╗ahy medzi funkciami

 i) eiae-ia = (cosa + isina)(cosa - isina) = cos2a + sin2a = 1
 ii) tg2a + 1 = (cos2a + sin2a)/cos2a = 1/cos2a

Funkcia sina cosa tga cotga
sina= sina (1-cos2a) tga/(1+tg2a) 1/(1+cotg2a)
cosa= (1-sin2a) cosa 1/(1+tg2a) cotga/(1+cotg2a)
tga= sina/(1-sin2a) (1-cos2a)/cosa tga 1/cotga
cotga= (1-sin2a)/sina cosa/(1-cos2a) 1/tga cotga

Funkcie s·Φtu a rozdielu

 ei(a+b) = eiaeib
 cos(a+b) + isin(a+b) = (cosa + isina)(cosb + isinb) =
 = cosacosb - sinasinb + i(cosasinb + sinacosb)

sin(a b) = cosasinb sinacosb sin(2a) = 2sinacosa
  sin2(a/2) = (1 - cosa)/2
cos(a b) = cosacosb sinasinb cos(2a) = cos2a - sin2a
  cos2(a/2) = (1 + cosa)/2
tg(a b) = (tga tgb)/(1 tgatgb) tg(2a) = 2tga/(1 - tg2a)
  tg2(a/2) = (1 - cosa)/(1 + cosa)
cotg(a b) = (cotgacotgb 1)/(cotgb cotga) cotg(2a) = (cotg2a - 1)/(2cotga)
  cotg2(a/2) = (1 + cosa)/(1 - cosa)

S·Φty a rozdiely funkciφ

 cos(a + b) + cos(a - b) = cosacosb - sinasinb + cosacosb + sinasinb =
 = 2cosacosb = |substit·cia a = (x + y)/2, substit·cia b = (x - y)/2| =
 = 2cos[(x + y)/2]cos[(x - y)/2] = cosx + cosy

sina + sinb = 2sin[(a + b)/2]cos[(a - b)/2]
sina - sinb = 2cos[(a + b)/2]sin[(a - b)/2]
cosa + cosb = 2cos[(a + b)/2]cos[(a - b)/2]
cosa - cosb = -2sin[(a + b)/2]sin[(a - b)/2]
tga tgb = sin(a b)/(cosacosb)
cotga cotgb = sin(b a)/(sinasinb)
tga cotgb = cos(a b)/(cosasinb)

S·Φiny funkciφ

 cos(a - b) - cos(a + b) = cosacosb + sinasinb - cosacosb + sinasinb =
 = 2sinasinb

sinasinb = [cos(a - b) - cos(a + b)]/2
cosacosb = [cos(a - b) + cos(a + b)]/2
sinacosb = [sin(a + b) + sin(a - b)]/2
tgatgb = (tga + tgb)/(cotga + cotgb)
cotgacotgb = (cotga + cotgb)/(tga + tgb)
tgacotgb = (tga + cotgb)/(cotga + tgb)

Funkcie nßsobkov uhlov

 e3ia = (eia)3
 (cos3a + isin3a) = (cosa + isina)3
 cos3a + isin3a = cos3a + 3icos2asina + 3i2cosasin2a + i3sin3a
 cos3a + isin3a = cos3a - 3cosasin2a + i(3cos2asina + sin3a)

sin3a = 3sina - 4sin3a
sin4a = 8sinacos3a - 4sinacosa
sin5a = 16sinacos4a - 12sinacos2a + sina
sinna = nsinacosn-1a - C(3,n)sin3acosn-3a + C(5,n)sin5acosn-5a - ..
cos3a = 4cos3a - 3cosa
cos4a = 8cos4a - 8cos2a + 1
cos5a = 16cos5a - 20cos3a + 5cosa
cosna = cosna - C(2,n)sin2acosn-2a + C(4,n)sin4acosn-4a - ..