Download Last Night`s Homework:

Last Night's Homework:
pg. 281 #18­60 Every 3rd Problem
18.
21.
24.
27.
30.
33.
36.
39.
42.
­16o 45'
286o 52' 48"
23.242o
173.410o
­1080o
­2700o
1440o
133o + 360ko; 473o; ­247o
­305o + 360ko; 55o; ­665o
45.
48.
51.
54.
57.
60.
40o; I
339o; IV
III
23o
35o
90k where k is an integer
1
2
Today's Objectives:
Find the values of the six trigonometric ratios for acute angles of right triangles.
Find the value of a trigonometric ratio given its cofunction.
Tomorrow:
Quiz 5­1 ­ 5­2
opposite side
hypotenuse
θ
legs
adjacent side
3
Trigonometric Ratios:
sine θ
sinθ
sinθ = opp/hyp
cosine θ
cosθ
cosθ = adj/hyp
tangent θ
tanθ
tanθ = opp/adj
e
us
Definition
ten
Symbols
po
hy
Words
opposite
defined by the ratios of the sides of the right triangles
θ
adjacent
Reciprocal Trigonometric Ratios
Words
Symbols
Definition
cosecant θ
csc θ
csc θ = 1/sin θ = hyp/opp
secant θ
sec θ
sec θ = 1/cos θ = hyp/adj
cotangent θ
cot θ
cot θ = 1/tan θ = adj/opp
4
Find the values of the six trig ratios for
C
B.
15 cm
B
8 cm
A
NOTE: If you do this with your calculator,
be sure you are in DEGREE mode.
Cofunctions
sin θ = cos(90o - θ)
tan θ = cot(90o - θ)
sec θ = csc(90o - θ)
cos θ = sin(90o - θ)
cot θ = tan(90o - θ)
csc θ = sec(90o - θ)
5
Homework:
pg. 288 #10­31 Every 3rd
6