Question

Can you guide me through this?

Answer 1

so We are using cosine law right?

Answer 2

looks like sine or cosine law

Answer 3

solve for angle B using law of cosines... then use that with the law of sines..

Answer 4

Law of cosines followed by law of sines

Answer 5

We would have b² = a²+c² - 2(a)(b) cos (B). Right?

Answer 6

yes

Answer 7

oops -2ac cosB

Answer 8

Wait, I wrote wrong one,

It would be this right?
6²+9²-2(6)(9)*cos(B)

Answer 9

Then Id get 117 - 108 * cos(B). Or is it wrong here?

Answer 10

I used a calculator. by 36+81= 117
2*6*9= 108
cos(110)= -0.342

Answer 11

so is it 9* cos(110) then?

Answer 12

6²+9²-2(6)(9)*cos(110)

Answer 13

Id get -3.07818

Answer 14

If you type
81+36-2*6*9*cos(110)=
in the google search window it will find 224.89

Answer 15

What? Im getting 153.93 in my calculator

Answer 16

Weird, I put exactly that, and I get 153

Answer 17

no you are right.

Answer 18

Ohh. okok

Answer 19

So from here, what do we do?

Answer 20

google was treating the 110 as in radians. You have to tell it degrees.

Answer 21

one sec

Answer 22

whats the value of b?

Answer 23

you just found b squared= 153.93

Answer 24

oh, nvm sorry

Answer 25

I know, I got confused coz i was looking at the wrong diagram

Answer 26

Is it sin(100) or (110)?

Answer 27

65
phi 2
First, take the square root to find side b

now law of sines
sin(A)/6 = sin(110)/b (fixed my typo)

Answer 28

I would then get .0061

Answer 29

sin(A)= 6*sin(110)/12.407 (you did take the square root, right?)

Answer 30

Oh. thats right, I didnt take the sqrt

Answer 31

Then, I woudl get 0.467

Answer 32

is the answer 27 degrees?

Answer 33

yes

Answer 34

THank you so much Phi!

Answer 35

1 question

Answer 36

are you an engineer student at MIT?

Answer 37

No I graduated. Before I went to MIT I couldn't spell inginere, now I are one.

Answer 38

Ohhh, I was just asking coz my sisters friend is taking his masters at MIT. I just wanted to see if maybe you knew him.

Answer 39

Anyways, Thank you so much! I really appreciate your help:)

Answer 40

btw, how did you get 0.467 I got something like sinA= 0.454

Answer 41

I thik its because in my calcualtor, when i get the sqare of 153.93. I get 12.164 instead of 12.407

Answer 42

no thats not it.

Answer 43

It's good to track down any mistakes and fix them so you don't get into bad habits.

Answer 44

Good point, I will look into it. Thank you:)

Answer 45

yw