sin2x + cos2x = 1
sin(a+b) = sina.cosb + sinb.cosa
sin(a-b) = sina.cosb - sinb.cosa
cos(a+b) = cosa.cosb - sina.sinb
cos(a-b) = cosa.cosb + sina.sinb
tana + tanb
tan(a+b) = ----------------
1 – tana.tanb
tana - tanb
tan(a-b) = ----------------
1 + tana.tanb
cota.cotb - 1
cot(a+b) = ----------------
cota + cotb
cota.cotb + 1
cot(a-b) = ----------------
cota - cotb
sin2a = 2.sina.cosa
cos2a = cos2a – sin2a
cos2a = 2.cos2a – 1
cos2a = 1 – 2.sin2a
2.tana
tan2a = -----------
1 – tan2a
cot2a - 1
cot2a = ------------
2.cota
a + b a - b
sina + sinb = 2 . sin------- . cos-------
2 2
a + b a - b
sina - sinb = 2 . cos------- . sin-------
2 2
a + b a - b
cosa + cosb = 2 . cos------- . cos-------
2 2
a + b a - b
cosa - cosb = -2 . sin------- . sin-------
2 2
cos(a-b) - cos(a+b)
sina.sinb = -----------------------
2
cos(a+b) + cos(a-b)
cosa.cosb = -----------------------
2
sin(a+b) + sin(a-b)
sina.cosb = -----------------------
2
Konu: Trigonometrik Formuller 
