Circular Measure, Representation Of Data, Trigonometry Flashcards
Write 360° in radians
2pi
To convert from ° to rad?
× pi/180
To covert from rad to °
× 180/pi
Number of radians is in a complete revolution is:
No of times radius divides into the circumference
What is 1rad or 1c
An arc equal in length to radius, subtended at an angle of 1 radian at the centre.
Length of an arc in radians
r theta
Area of a sector in rad
0.5× r^2 × theta
What is the basic trigonometric identity
sin2x + cos2x =1
*Ie sinx whole squared
Tan2 theta =
sin2 theta / cos2 theta
What are the 4 quadrants. State and explain
1st- A 0-90, all are positive
2st - S 90-180, only sin is postive
3rd- 180-270, only tan is positive
4th- C 270-360, only cos is positive
And vice versa for negative angles
What to do to make negative angle to positive?
Add 360
State properties of each of the 3 functions graphs
Sin- continuous curve, -1<=sin0<=1, period is 2pi(repeated)
Cos- continuous curve, -1<=cos0<=1, period is 2pi(repeated)
Tan- not continuous has breaks, range values of tan theta is unlimited, period is pi(repeated)
What is sin cos tan 0?
0
1
0
What is sin cos tan 30
1/2
√3/2
1/√3
What is sin cos tan 45
1/√2
1/√2
1
What is sin cos tan 60
√3/2
1/2
√3