Trigonometry Flashcards
0
Q
Double angle formula for cos:
A
Cos2A = cos(^2)A - sin(^2)A
Cos2A = 2cos(^2)A - 1
Cos2A = 1 - 2sin(^2)A
1
Q
Double angle formula for sin:
A
Sin2A = 2sinAcosA
2
Q
Double angle formula for tan:
A
Tan2A = 2tanA
————-
1 - tan(^2)A
3
Q
Pythagorean expression for sin and cos:
A
sin(^2)A + cos(^2)A = 1
4
Q
Pythagorean expression for cot and cosec:
A
1 + cot(^2)A = cosec(^2)A
5
Q
Pythagorean expression for tan and sec:
A
tan(^2)A + 1 = sec(^2)A
6
Q
cosecA =
A
sinA
7
Q
secA =
A
cosA
8
Q
cotA =
A
tanA
9
Q
cotA =
A
sinA
10
Q
When using Rsin(x+-a) or Rcos(x-+a)…
A
Rcosa=b or Rsina=c and
__________
R= |b^2 + c^2 PYTHAG TO FIND R
