Trigonometry Flashcards
What is the cosine rule formula
a^2= b^2 + c^2 -2bcCOSA
what is the area formula for triangle
1/2 ab sinc
Where does SIN GRAPH cross x axis, postive and negative
0, 180,360 -180, -360
When is SIN GRAPH at 1
when theta is 90,
it is -1 WHEN THETA is 270 or -90
When does SIN graph repeat
every 360
When does COS graph cross x axis
90, 270
when is COS GRPAH AT 1
AND -1?
at 1 is 0,360
-1 at 180
When does COS GRAPH repeat
360
When does tan graph cross x axis
0,180,360
Where are the symptotes for TAN GRAPH
90,270
When does TAN GRPAH repeat
every 180
how else can you write
sin(180 -θ)
tan(180-θ)
cos(180-θ)
= -cos θ
-sin θ
-tan θ
how else can you write
cos(90-θ)
and
sin(90-θ)
cos(90-θ) = sin θ
and
sin(90-θ) = cos θ
if it says obtuse angle, what do they mean you to do
obtuse, so it means MORE THAN 90, LESS THAN 180
- see if its cos tan or sin
- then see if it should be + OR - in CAST DIAGRAM
- and then correct the +- if needed
If it asks for bearing from point B to A,
And point A is lower than point B,
whats the angle going to be, in terms of inside the square or outside
outside, so basically 360 -θ
Whats a reflex angle
more than 180, less than 360
