Trigonometric Identities and Formulae Flashcards
1
Q
tanx
A
sinx/cosx
2
Q
sin2(x) + cos2(x)
A
1
3
Q
sin(-x)
A
-sinx
4
Q
cos(-x)
A
cosx
5
Q
tan(-x)
A
-tanx
6
Q
sin(a+b)
A
sinacosb + cosasinb
7
Q
cos(a+b)
A
cosacosb - sinasinb
8
Q
tan(a+b)
A
(tana + tanb)/(1-tanatanb)
9
Q
cscx
A
1/sinx
10
Q
secx
A
1/cosx
11
Q
cotx
A
1/tanx
12
Q
tan2(x) + 1
A
sec2(x)
13
Q
1 + cot2(x)
A
csc2(x)
14
Q
arctanx
A
tan-1(x)
15
Q
arcsinx
A
sin-1(x)
16
Q
arccosx
A
cos-1(x)
17
Q
tan(2x)
A
2tanx/(1-tan2(x))
18
Q
sin(2x)
A
2sinxcosx
19
Q
cos(2x)
A
2cos2(x)-1 cos2(x) - sin2(x) 1-2sin2(x)
20
Q
arc length
A
xr (xº/360)2πr (xº/180)πr
21
Q
area of a sector
A
(1/2)xr^2 (xº/360)πr^2
22
Q
area of a triangle
A
(1/2)baseheight (1/2)absinC
23
Q
cosrule
A
c^2 = a^2 + b^2 -2abcosC
24
Q
sin rule
A
sinA/a =sinB/b
