This week we will start reviewing for the trig exam
so i will start posting trig notes for each chapter
Angles are measured in DEGREES (possibly with either minutes' or minutes' andseconds")
and RADIANS
To find minutes
multiply what is behind the decimal by 60
and take whole number as minutes'
To find seconds
multiply what is behind the decimal of minutes by 60
then whats behind that decimal by 3600 to get seconds'
To get radians
degrees x pi/180degrees
((***Remember to always ues exact answers))
((*** Remember to never plug pi into calculator))
Unit Circle:
90 degs. = (0,1) pi/2
180 degs. = (-1,0) pi2
70 degs. = (0,-1) 3pi/2
360 degs. = (1,0) 2pi
sin=y/r
cos=x/r
tan=y/x
cot=x/y
sec=r/x
csc=r/y
i need someone to provide me with the formulas neccessary to have memorized for chapter eight and then i need someone to help me figure out any tricks they may know for solving chapter eight
a quick tip overview of chapter eight may be easiest.
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These are the identities to memorize:
ReplyDeleteReciprocal Relationships:
cscΘ=1/sinΘ
secΘ=1/cosΘ
cotΘ=1/tanΘ
Relationships with Negatives:
sin -Θ= -sinΘ and cos -Θ= -cosΘ
csc -Θ= -cscΘ and sec -Θ= -secΘ
tan -Θ= -tanΘ and cot -Θ= -cotΘ
Pythagorean Relationships:
sin²Θ+cos²Θ=1
1+tan²Θ=sec²Θ
1+cot²Θ=csc²Θ
Cofunction Relationships:
sinΘ=cos(90°-Θ) and cosΘ=sin(90°-Θ)
tanΘ=cot(90°-Θ) and cotΘ=tan(90°-Θ)
secΘ=csc(90°-Θ) and cscΘ=sec(90°-Θ)
***Cautions***
You cannot divide trig functions to cancel them
You can move everything to one side and factor out a trig function
You can divide by a trig function to create a new one
Helpful information:
I - II : make negative then add 180
I- III : add 180
I - IV : make negative then add 360
Sin- positive in 1 and 2... negative in 3 and 4
Cos- positive in 1 and 4. ..negative in 2 and 3
Tan- positive in 1 and 3... negative in 2 and 4