trigo formulasidentities Flashcards
1
Q
cos(x+y)=
A
cosxcosy-sinxsiny
2
Q
cos(x-y)=
A
cosxcosy+sinxsiny
3
Q
cos(pi/2 - x)=
A
sinx
4
Q
cos(pi/2 +x)=
A
-sinx
5
Q
sin(pi/2-x)=
A
cosx
6
Q
sin (pi/2 +x )=
A
cosx
7
Q
sin(x+y)=
A
sinxcosy+cosxsiny
8
Q
sin(x-y)=
A
sinxcosy-cosxsiny
9
Q
cos(pi-x)=
A
-cosx
10
Q
sin(pi-x)
A
sinx
11
Q
cos(pi+x)
A
-cosx
12
Q
sin(pi+x)
A
-sinx
13
Q
cos(2pi-x)
A
cosx
14
Q
sin(2pi-x)
A
-sinx
15
Q
tan(x+y)
A
tanx+tany/ 1-tanxtany
16
Q
tan(x-y)
A
tanx-tany/ 1+tanxtany
17
Q
cot(x+y)
A
cotxcoty-1 / coty+cotx
18
Q
cot(x-y)
A
cotxcoty+1/ coty-cotx
19
Q
cos2x=cos^2x-sin^2x=2cos^2x-1=
A
1-2sin^2x= 1-tan^2x / 1+tan^2x
20
Q
sin2x=2sinxcosx=
A
2tanx/1+tan^2x
21
Q
tan2x=
A
2tanx/1-tan^2x
22
Q
sin3x=
A
3sinx-4sin^3x
23
Q
cos3x=
A
4cos^3x-3cosx
24
Q
tan3x=
A
3tanx-tan^3x/1-3tan^2x
25
Q
cosx+cosy=
A
2cos x+y/2 cos x-y/2
26
Q
cosx-cosy=
A
-2sin x+y/2 sin x-y/2
27
Q
sinx+siny=
A
2sin x+y/2 cos x-y/2
28
Q
sinx-siny
A
2cos x+y/2 sin x-y/2
