Trigonometry Flashcards
cos² + sin² = ?
1
cos(-x) = ?
cos(x)
sin(-x) = ?
-sin(x)
cos(π + x) = ?
-cos(x)
sin(π + x) = ?
-sin(x)
cos(π/2 - x) = ?
sin(x)
sin(π/2 - x) = ?
cos(x)
cos(π/2 + x) = ?
-sin(x)
sin(π/2 + x) = ?
cos(x)
cos(0) = ?
1
sin(0) = ?
0
cos(π/6) = ?
√3/2
sin(π/6) = ?
1/2
cos(π/4) = ?
√2/2
sin(π/4) = ?
√2/2
cos(π/3) = ?
1/2
sin(π/3) = ?
√3/2
cos(π/2) = ?
0
sin(π/2) = ?
1
cos u = cos v implies ….
u = v + 2kπ
OR
u = -v + 2kπ
sin u = sin v implies ….
u = v + 2kπ
OR
u = π-v + 2kπ
cos(a+b) = ?
cos(a)cos(b) - sin(a)sin(b)
cos(a-b) = ?
cos(a)cos(b) + sin(a)sin(b)
sin(a+b) = ?
sin(a)cos(b) + cos(a)sin(b)
sin(a-b) = ?
sin(a)cos(b) - cos(a)sin(b)
cos(2*a) = ? (3 forms)
1) cos²(a) - sin²(a)
2) 1 - 2sin²(a)
3) 2cos²(a) - 1
sin(2*a) = ?
2sin(a)cos(a)
cos²(a) = f(cos(2*a))
(1 + cos(2*a)) / 2
sin²(a) = f(sin(2*a))
(1 - cos(2*a)) / 2
cos(a)*cos(b) = ?
1/2*[cos(a+b) + cos(a-b)]
sin(a)*sin(b) = ?
1/2*[cos(a-b) - cos(a+b)]
sin(a)*cos(b) = ?
1/2*[sin(a+b) + sin(a-b)]
