Question

Find the complete solution in radians of the equation. I really need help on this one. There are pictures provided for the problem and possible answers. Please tell me how you got your answer, and thank you in advance for your help.

Answer 1

Here is the problem itself.

Answer 2

And here are the possible answers.

Answer 3

those are 5 separate problems, not 1 problem and 4 answers

Answer 4

I'm sorry, but it is a multiple choice question. The first picture I uploaded is the problem and I need to find the complete solution in radians.

Answer 5

the very first thing to do is convert sin^2 theta into 1-cos^2 theta

Answer 6

then, factor the equation and solve.

Answer 7

@inkyvoyd thank you, could you please show me how so I can write it down in my notebook?

Answer 8

note that sin^2 theta+cos^2 theta=1
therefore sin^2 theta=1-cos^2 theta
thus
you have cos th (1-cos^2 th)-3cos th /4=0

Answer 9

then factor the equation for cos th. Tell me what you get.

Answer 10

@inkyvoyd I'm sorry, but I'm still a little lost. Would it be too much to ask for more help?

Answer 11

What part are you having trouble understanding?

Answer 12

The thing is I'm trying to put it into my calculator and I'm having trouble navigating it. Could you show me how to do the equation?

Answer 13

If you had followed my directions you would not have trouble. The reason you are lost is because you are relying on your calculator. Unless your calculator has CAS capabilities, I believ eyou should follow what I say.

Answer 14

you cannot solve an algebraic equation by entering it into your calculator. You must first isolate the variable, and even then there is no need for a calculator in this problem, nor will a calculator be helpful.

Answer 15

What you need to do is factor the equation, as I have mentioned.

Answer 16

let me know what you get...

Answer 17

@inkyvoyd I'm sorry, but I don't seem to know how to do this in radians. I tried it out and it came out all strange and not even close to any of the possible choices I have.

Answer 18

@lalaloopsy8888 , factoring has nothing to do with radians. I'm here to work out this problem step by step with you. If you want to continue, then follow my directions please.
Factor the equation as I have given you.

Answer 19

@inkyvoyd What I got was. cos th/2

Answer 20

Okay, I'm out of patience amigo. I have waited here for each of your responses, none of which are relevant to what I am talking about. Three strikes and you're out. GL.

Answer 21

@inkyvoyd Alright, sir, I'm so sorry that I upset you. I'm just really lost and I needed guidance. In no way should my inability to comprehend reflect on my sincerity. Once again, I am so sorry to have upset you.

Answer 22

Eh, I'm a bit edgy due to lack of sleep. I'll hand the problem over to some one more competent at this time of day. @abb0t @Confusionist @jagatuba and all you useless people in chat, please help this dude

Answer 23

Inky, you're here to do a job. Do it or leave. >_>

Answer 24

inky is leaving. Confusionist is in.

Answer 25

:c You had one job. ONE JOB.

Answer 26

Thank you for participating. I'm really lost here and I don't even know where to start. Could you please help?

Answer 27

Man you need to learn LaTeX or use the equation generator. It's too big of a pain to sift through all those jpegs.

Answer 28

\[\cos \theta \sin^2 \theta - 3\cos \theta/4=0\]

Answer 29

This was my question: Find the complete solution in radians of the equation

Answer 30

do you want help ?

Answer 31

woops left out a solutions

Answer 32

I will use t instead of theta.
cos t sin^2 t - 3/4 cos t . factor out cos t
cos t ( sin^2 t - 3/4) = 0
cos t = 0 or sin^2 t - 3/4 = 0
cos t = 0 or sin^2 t = 3/4
cos t = 0 or sin t = +/- sqrt(3) / 2
t = cos^-1 (0) or t = +/- sin^-1 [ sqrt(3) / 2 ]
t = cos^-1(0) or t = sin^-1[ sqrt(3)/2] or t = - sin^-1[sqrt(3)/2]
t= { pi/2 + pi*n , pi/3 + 2pi*n , 2pi/3+ 2pi*n, 4pi/3 + 2pi*n, 5pi/3 + 2pi*n}

Answer 33

@perl Thank you so much! It was so nice of you to help me, I was so confused before. I'll write this procedure down. Thank you!

Answer 34

so its your last choice,
http://assets.openstudy.com/updates/attachments/52c8ef01e4b04f95cb848f68-lalaloopsy8888-1388900177669-question20145.jpg

Answer 35

@perl Thank you!