S2 Trigonometry Flashcards
1
Q
By definition, sin a =
A
Opposite side/hypotenuse of a right triangle with angle a
2
Q
By definition, cos a =
A
Adjacent side/hypotenuse of a right triangle with angle a
3
Q
By definition, tan a =
A
Opposite side/adjacent side of a right triangle with angle a
4
Q
For a triangle with sin a = A/B, cos a =
A
√(B2 - A2)/B
(opposite side : hypotenuse = A : B, then by pythagoras theorem we can find adjacent : hypotenuse.)
5
Q
For a triangle with cos a = A/B, sin a =
A
√(B2 - A2)/B
6
Q
For a triangle with tan a = A/B,
sin a =; cos a =
A
sin a = A/√(B2 + A2)
cos a = B/√(B2 + A2)
7
Q
sin0º
A
0
8
Q
sin30º
A
1/2
9
Q
sin45º
A
√2/2
10
Q
sin60º
A
√3/2
11
Q
sin90º
A
1
12
Q
cos0º
A
1
13
Q
cos30º
A
√3/2
14
Q
cos45º
A
√2/2
15
Q
cos60º
A
1/2
