Trigonometry Flashcards
How do you convert degrees to radians?
(Pi)/180
How do you convert radians to degrees?
180/(pi)
180 degrees =?
Pi
1 rad =?
180/(pi)
1 degree =?
(Pi)/180
How do you find coterminal angles?
- ) find an angle between desired values.
2. ) either add or subtract. (Finding negative coterminals)
How do you find length of an arc?
S=theta(radius)
How do you find the central angle of theta?
Theta= s/r
How do you find area of a sector?
A=1/2r^2theta
How do you find points moving from linear speed to circular speed?
Angular speed= w= theta/time
Linear speed= v=s/t
Sin theta =?
Opposite/hypotenuse
Cos theta=
Adjacent/hypotenuse
Tan theta =
Opposite/adjacent
Sin 30=?
1/2
Cos 30=?
Sq. rt. 3 over 2
Tan 30 =?
Sq. rt. 3 over 3
Sin 45 =?
Sq rt 2/2 (likewise for cos)
Tan 45=
1
Sin 60=?
Sq rt 3 over 2
Cos 60=
1/2
Tan 60=?
Sq rt 3
Sin theta=
y/r
Cos theta=
x/r
Tab theta=
x/y
In quadrant 1:
All functions are positive
In quadrant 2:
Sin and csc are positive, the rest are negative
In quadrant 3:
Tan and cot are positive, the rest are negative
In quadrant 4,
Cos and sec are positive, the rest are negative
How do you find the reference angle?
Subtract the necessary degree (180, 360, etc) and subtract or add that value
How do you evaluate trigonometric functions for any angle?
Find the reference angle theta associated with the angle theta, determine the sign (quadrant)
What are the reciprocal and Pythagorean identities?
Csc= 1/sin Sec= 1/cos Cot= 1/tan Tan= sin/cos Cot= cos/sin
How do you find the area of a triangle?
1/2absin(theta)
