-
-
Find the length of the altitude to
P
Q
¯
p q bar in the triangle below.
- Find the area of
Δ
PQR
cap delta .
-
Reasoning If you solve for cos A in the Law of Cosines, you get
cos
A
=
b
2
+
c
2
−
a
2
2
b
c
.
cosine eh equals . fraction b squared , plus , c squared , minus , eh squared , over 2 b c end fraction . .
- Use this formula to explain how cos A can be positive, zero, or negative, depending on how
b
2
+
c
2
b squared , plus , c squared compares to
a
2
.
eh squared , .
- What does this tell you about
∠
A
angle eh in each case?
Standardized Test Prep
GRIDDED RESPONSE
Use the diagram for Exercises 54–59. Angle measures are in degrees. Give each answer to the nearest tenth.
SAT/ACT
- Let
a
=
23.2
eh equals , 23.2 ,
b
=
18.5
b equals , 18.5 , and
m
∠
C
=
m angle c equals 42. Find c.
- Use the information in Question 54 to find
m
∠
A
.
m angle eh .
- Suppose
a
=
45.25
eh equals , 45.25 ,
b
=
39.75
b equals , 39.75 , and
c
=
20.65
c equals , 20.65 . Find
m
∠
B
.
m angle b .
- Use the information in Question 56 to find
m
∠
C
.
m angle c .
- Suppose
b
=
11.0
b equals , 11.0 ,
c
=
11.7
c equals , 11.7 , and
m
∠
A
=
m angle eh equals 22. Find the length of the altitude from A.
- Use the information in Question 58 to find the area of
Δ
ABC
cap delta to the nearest tenth.
Mixed Review
- In
Δ
RST
,
m
∠
R
=
37
°
,
m
∠
T
=
59
°
,
cap delta and
T
S
=
12
t s equals 12 in. Find RS. See Lesson 14-4.
- In
Δ
JKL
,
m
∠
L
=
71
°
,
j
=
11
cap delta m, and
m
∠
K
=
46
°
.
m angle k equals , 46 degrees . Find k.
- In
Δ
MNP
,
m
∠
N
=
42
°
,
n
=
21
cap delta in., and
m
∠
M
=
57
°
.
m angle m equals , 57 degrees . Find m.
- In
Δ
DEF
,
m
∠
F
=
91
°
,
d
=
17
cap delta mm, and
f
=
21
f equals 21 mm. Find
m
∠
D
.
m angle d .
Identify the period and describe two asymptotes for each function. See Lesson 13-6.
-
y
=
y equals tan 0.
5
θ
5 theta
-
y
=
tan
3
π
2
θ
y equals tangent . fraction 3 pi , over 2 end fraction , theta
-
y
=
tan
(
−
3
θ
)
y equals tangent open negative 3 theta close
-
y
=
tan
π
θ
y equals tangent pi theta
Get Ready! To prepare for Lesson 14-6, do Exercises 68–71.
Complete the identities. See Lesson 14-1.
-
csc
θ
=
1
co-secant theta equals , fraction 1 , over table with 1 row and 1 column , row1 column 1 , , end table end fraction
-
sec
θ
=
1
secant theta equals , fraction 1 , over table with 1 row and 1 column , row1 column 1 , , end table end fraction
-
cos
2
θ
+
sin
2
θ
=
□
cosine squared , theta plus , sine squared , theta equals white square
-
1
+
cot
2
θ
=
□
1 plus , co-tangent squared , theta equals white square