[ALG2] The Unit Circle - TRIG Flashcards
radians to degrees
180/pi
degrees to radians
pi/180
acronym for the quadrants
All (all)
Students (sine)
Take (tangent)
Calculus (cosine)
trick for 30/45/60 degrees
1) put 30, 45, 60
2) write 123 going down
3) write 123 going up
4) put everything over 2
5) put radicals in all numerators (1 is already a square root)
cosecant is the inverse of
sine
secant is the inverse of
cosine
cotangent is the inverse of
tangent
sin, cos, tan at 0/360
0, 1, 0
sin, cos, tan at 90
1, 0, undefined
sin, cos, tan at 270
-1, 0, undefined
something is undefined when
it is put over 0
tangent is
sine/cosine
cotangent is
cosine/sine
sine is the _ coordinate
y
cosine is the _ coordinate
x
reference angle is
from the angle measure back to x axis
how do u get coterminal angles
add or subtract 360
to get from a negative to positive angle u
add 360
to get from (larger than 360) to 360 or less u
subtract 360
formula to get sine if given cosine
x squared + y squared = 1
relationships for 45-45-90 triangles
sl ll hyp
n, n, n radical 2
relationships for 30-60-90 triangles
sl ll hyp
n, n radical 3, 2n
sin is
opp/hyp
cosine is
adj/hyp
tan at 0/360
0
tan at 30
radical 3/3
tan at 45
1
tan at 60
radical 3
tan at 90
undefined
tan at 180
0
tan at 270
undefined
cosecant and secant are
1/sin
1/cosine
first quadrant has
0-90
second quadrant has
90-180
third quadrant has
180-270
fourth quadrant has
270-360
how to find exact trig value
1) find reference angle (convert to degrees and make it between 0-360 if necessary)
2) will it be neg or pos? (based on quadrant)
3) write it as (pos/neg)(function)(ref angle)
4) get the value u need
5) adjust signs if necessary
