Question

Help please

Answer 1

any attempts yet? AC is a very straightforward law of cosines case

c^2 = a^2 + b^2 - 2abcos(C)

Answer 2

c^2 = a^2 + b^2 - 2abcos(C)
c^2=a^2+10^2-2*a*10(Cos (C)

Answer 3

good but you need to keep going and plug in the angle and the other side value (8)

Answer 4

oh right

Answer 5

c^2 = a^2 + b^2 - 2abcos(C)
c^2=8^2+10^2-2*8*10(Cos (110)
c^2=14.79

Answer 6

almost, it's c that's equal to 14.79 not c^2

Answer 7

anyway for part II you can set up

14.79/sin(110) = 10/sin(C)

to solve for angle C

Answer 8

14.79/sin(110) = 10/sin(C)
C=6.28

Answer 9

you were a bit closer the first time

sin(C) = 10*sin(110)/14.79

then take the arcsin of both sides

make sure your result is in degrees not radians

Answer 10

1.14?

Answer 11

10*sin(110)/14.79 = ?

Answer 12

0.64

Answer 13

good then take the arcsin of that

then convert to degrees

Answer 14

39.79

Answer 15

good, so that's your solution

Answer 16

Find the measure of angle A using any method. this is the third part


a^2=b^2+c^2-2*b*c(CosA)
8^2=10^2+14.79^2-2*10*14.79 (Cos A)
A=0.86

Answer 17

you already have angle C and angle B so finding angle A is a matter of using the fact that all angles in a triangle sum up to 180

going to get lunch, be back in a bit

Answer 18

180-39.79-110=30.21

Answer 19

for the missing angle

Answer 20

good

for vertical shift pay attention to what is being added/subtracted from the entire cos expression

Answer 21

-3

Answer 22

-3 is being multiplied not added or subtracted

Answer 23

+1

Answer 24

good

any ideas on the graph? I would recommend starting with x = 0 and figuring out what direction to go from there

Answer 25

like, if you plug in x = 0 into -3cos(2x) + 1 what do you get?

Answer 26

good, then from pi to 2pi it's the same shape just inverted

it will end up going off the graph a bit

Answer 27

it needs to be continuous with the points you have already drawn

Answer 28

wait a sec

Answer 29

ok

Answer 30

oh wait since it repeats itself every pi units you just need to draw that same shape from pi to 2pi

Answer 31

good, then its symmetric about the y-axis so can just make the left side exactly like the right side

Answer 32

good

Answer 33

@Vocaloid

Answer 34

ya there

Answer 35

for part I the question is somewhat misleading because displacement and position are not the same thing

that being said I believe they would just want you to plug in t = 0 into the function

part II: maximum displacement = amplitude

part III: period = 2pi/b

part IV: frequency = 1/period from part III

Answer 36

d=3sin(8pi(0))-2
d=2

Answer 37

for part one

Answer 38

part II

0

Answer 39

part III

2pi/0

Answer 40

for part I check the sign again, it should be -2 not 2

Answer 41

d-2

Answer 42

d=-2

Answer 43

for part II: the amplitude is not 0

check what number the sin function is being multiplied by

Answer 44

3

Answer 45

for part I its d=-2 right

Answer 46

yes

Answer 47

okay and amplitude is 0

Answer 48

then for part III calculate 2pi/b

note that b is the number being multiplied to x

Answer 49

amplitude is not 0

Answer 50

i meaN 3

Answer 51

sorry lol

Answer 52

2pi/3 = 120 degrees

Answer 53

note that b is not 3

b is the number being multiplied to t

Answer 54

8pi?

Answer 55

good

so period = 2pi/(8pi)

Answer 56

2pi/(8pi)= 1/4

Answer 57

good

then for part IV frequency = 1/period

Answer 58

1/(1/4)=4

Answer 59

awesome so that's it