θ=Theta (they-da)
C
represents an unknown
angle measurement!
Aim: What are the 6 trigonometric functions?
use
ten
o
p
hy
Leg opposite to angle A
HW#2 A
Do Now: Recall what SOHCAHTOA means? When do we use it?
θ
Leg adjacent to angle A B
Trigonometric Ratios:
sinθ = opposite leg
hypotenuse
cosθ = adjacent leg
hypotenuse
tanθ = opposite leg
adjacent leg
SOHCAHTOA
There are 3 more trig functions:
1
1
csc = sec = θ
θ
sin θ
cos θ
Secant
1
cot =
θ
tan
θ
Cosecant
Cotangent
THESE ARE THE RECIPROCAL FUNCTIONS OF SIN,
COS, AND TAN!
Note: 1) In right triangle ABC with right angle C, AC=8 and BC=15. Find:
A
8
C
15
a) sin A g) sin B
b) cos A
h) cos B
c) tan A
i) tan B
d) sec A
j) sec B
e) csc A
k) csc B
B
f) cot A
4) Find to the nearest degree:
θ
a) sin = 0.9238
θ
3) Calculator Use:
Find: a) sin 39o d) csc 20o
b) cos 49o e) cot 53o
c) tan 70o
f) sec 84o
l) cot B
Example 5:
Ex 6) Solve for x to the nearest tenth.
Solve for θ (to the nearest degree)
1) x
b) cos = 0.1536
θ
42
c) tan = 4.1868
θ
3)
10
9
o
θ
25
d) csc = 2.9238
θ
4) 2) 3
e) cot = 0.7536
θ
f) sec = 9.5668
θ
θ
x
65
13
o