identities Flashcards
1
Q
sin (a/2) =
A
+- root (1-cos a)/2
2
Q
cos (a/2)=
A
+- root (1+cos a)/2
3
Q
tan (a/2)= (3 POSSIBILITIES)
A
+- root (1-cos a)/(1+cos a)
(sin a)/(1+cos a)
(1-cos a)/(sin a)
4
Q
sin2a =
A
2sinAcosA
5
Q
cos 2A= (3 POSSIBILITIES)
A
cos^2 A - sin^2 A
1-2sin^2 A
2cos^2 A -1
6
Q
tan 2A =
A
(2tanA)/(1-tan^2 A)
7
Q
sin (A+B)=
A
sinAcosB + cosAsinB
8
Q
sin(A-B)=
A
sinAcosB-cosAsinB
9
Q
cos (A+B)
A
cosAcosB - sinAsinB
10
Q
cos(A-B)
A
cosAcosB+sinAsinB
11
Q
tan(A+B)=
A
(tanA+tanB)/(1-tanAtanB)
12
Q
tan(A-B)
A
(tanA-tanB)/(1+tanAtanB)
13
Q
sin/cos=
A
tan
14
Q
cos/sin
A
cot
15
Q
sin^2+cos^2
A
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