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TRIGONOMETRY - Coggle Diagram
TRIGONOMETRY
Identities
Sin(90-θ)=cosθ
cos(90-θ)=sinθ
sin(θ)=sin(180-θ )
cos(θ)=cos(-θ)
-cos(θ)=(cos180-θ)
-sin(θ)=sin(-θ)
cos^2 θ+sin^2 θ=1
They are equalities between trigonometric functions
Sine rule
The sine rule relates the length of the sides of a triangle to the sines of their angles.
a/sin(A) = b/sin(B) = c/sin(C)
2 sides + 2 angles
Cosine rule
The cosine rule relates the length of the sides of a triangle to the cosines of their angles.
a^2 = b^2 + c^2 -2bc·cos(a)
(3 sides + 1 angle)
Applications
Bearings
A bearing is an angle measured from the north direction, going clockwise.
We used it with the unit circle
Elevation and depression
Elevation and depression determine if the angle is pointing up (elevation) or down (depression)
SinA= opp/hyp CosA= adj/hyp TanA= opp/adj
Can be used to find either a side or an angle
Trigonometric functions
Graph
sin(x)
Cos(x)
Pytagoras
(opp)^2 + (adj)^2 = (hyp)?
