_121_ R7 or 121 7/13
13)1580
13
28
26
20
13
7
Answer:
Replace
F
(
x
)
with
y
.
y
=
9
x
Interchange the variables.
x
=
9
y
Solve for
y
.
Tap for more steps...
y
=
x
9
Solve for
y
and replace with
F
−
1
(
x
)
.
Tap for more steps...
F
−
1
(
x
)
=
x
9
Step-by-step explanation:
Answer: 
<u>Step-by-step explanation:</u>
Given: cos x =
, x is in Quadrant 4
Use Pythagorean Theorem to find sin x:
8² + y² = 17²
y² = 17² - 8²
y² = 289 - 64
y² = 225
y = 15
→ sin x = 
Use the double angle formula to find cos (2x):

Answer: 36000
Step-by-step explanation:
try looking it up lol
63 = 9k
divide by 9 on each side to get k by itself
k = 7