Download θ = θ = θ = hypotenuse sec leg adjacent θ θ θ θ θ θ

PreCalculus Class Notes TFG2 Right Triangle Trigonometry
Sine
sin
le g o p p o s ite
h y p o te n u s e
s in θ =
Cosine
cos
cos θ =
Cosecant
csc
hypotenuse
leg opposite
1
csc θ =
sinθ
csc θ =
leg adjacent
hypotenuse
Tangent
tan
tanθ =
Secant
sec
sec θ =
hypotenuse
leg adjacent
sec θ =
leg opposite
leg adjacent
Cotangent
cot
cot θ =
1
cos θ
leg adjacent
leg opposite
cot θ =
1
tanθ
Labeling triangles
Example: Find the six trigonometric functions of θ. Figure above right.
sin θ
cos θ
tan θ
csc θ
sec θ
cot θ
Known trig values for special angles
sin θ
cos θ
tan θ
π
π
π
6
4
3
π
π
π
6
6
6
c
b
π
π
π
3
3
3
a
π
π
4
4
c
a
π
π
4
4
a
Find all the missing sides.
π
π
4
π
4
4
5
π
4
Memorize or reproduce? Look at patterns
π
π
π
6
4
3
sin θ
cos θ
tan θ
csc θ
sec θ
cot θ
Example: A right triangle with one angle of
π
6
has a hypotenuse of length 5. Find the lengths
of the two sides.
Example: A right triangle with one angle of
of the two sides.
π
4
has a hypotenuse of length 4. Find the lengths