Chapter 1: Common Radians w/cos and sin Flashcards
What are the first 4 45º radian measurements?
π/4
π/2 [2π/4]
3π/4
π [4π/4]
What are the second 4 45º radian measurements?
5π/4
3π/2 [6π/4]
7π/4
2π
What are the first 6 30º radian measurements?
π/6 π/3 [2π/6] π/2 [3π/6] 2π/3 [4π/6 5π/6 π [6π/6]
What are the second 6 30º radian measurements?
7π/6 4π/3 [8π/6] 3π/2 [9π/6] 5π/3 [10π/6] 11π/6 2π [12π/6]
cosine is on what axis?
X-axis
sine is on what axis?
Y-axis
“1-unit circle”
What is cos(2π)?
1
[2π (0º or 360º) is on (1,0)]
[cos (or: x-axis) is 1]
“1-unit circle”
What is sin(3π/2)?
-1
[3π/2 (270º) is on (0,-1)]
[sin (or: y-axis) is on -1]
“1-unit circle”
What is cos(9π)?
-1
[9π (8π {which is 4 revs} + π)]
[π is on (-1,0)]
[cos (or: x-axis) is on -1]
“1-unit circle”
What is cos(3)?
-.9986 [3 radians] [put calc into "RAD"] [double check: π=3.14 rads] [3 rads is Q II, cos (3) is negative]
“1-unit circle”
What is sin (30º)?
.5
[30 degrees]
[put calc into “DEG”]
[double check: 30º is in Q I, sin 30 is pos]
“1-unit circle”
What are the first 4 common cosines?
1
√3/2
√2/2
1/2
“1-unit circle”
What are the first 4 common sines?
0
1/2
√2/2
√3/2
“1-unit circle”
What are the second 4 common cosines?
0
- 1/2
- √2/2
- √3/2
“1-unit circle”
What are the second 4 common sines?
1
√3/2
√2/2
1/2
