Delete
Share
This Question is Closed
nelsonjedi
Best Response
You've already chosen the best response.
0
Do you have a calculator?
ygarcia
Best Response
You've already chosen the best response.
0
no
Abiilovee911
Best Response
You've already chosen the best response.
0
π=180∘
ygarcia
Best Response
You've already chosen the best response.
0
so I replace pi with 180?
Abiilovee911
Best Response
You've already chosen the best response.
0
yes
ygarcia
Best Response
You've already chosen the best response.
0
so it'd be 23*pi divided by 6?
Abiilovee911
Best Response
You've already chosen the best response.
0
exactly (:
ygarcia
Best Response
You've already chosen the best response.
0
thanks :)
Abiilovee911
Best Response
You've already chosen the best response.
0
welcome (:
ygarcia
Best Response
You've already chosen the best response.
0
Is 12.03 Right?
RolyPoly
Best Response
You've already chosen the best response.
0
cosine of a value cannot be larger than 1...
ygarcia
Best Response
You've already chosen the best response.
0
can you please explain?
RolyPoly
Best Response
You've already chosen the best response.
0
See the graph of cosine:|dw:1389756073553:dw|
ygarcia
Best Response
You've already chosen the best response.
0
yes
RolyPoly
Best Response
You've already chosen the best response.
0
Maximum of a y=cos x function is 1. Minimum of a y=cosx function is -1
ygarcia
Best Response
You've already chosen the best response.
0
so do I need to graph this?
nelsonjedi
Best Response
You've already chosen the best response.
0
|dw:1389756066410:dw|
RolyPoly
Best Response
You've already chosen the best response.
0
So, you cannot have COS 23pi/6 = 12.03
RolyPoly
Best Response
You've already chosen the best response.
0
\[\cos\frac{23\pi}{6} = \cos(3(2\pi) + \frac{5\pi}{6}) = \cos\frac{5\pi}{6} = ...?\]
nelsonjedi
Best Response
You've already chosen the best response.
0
Using the attached drawing where does 23/pi fall?
Lethal
Best Response
You've already chosen the best response.
1
Okay sir's let me tell you that.
Cos23pi/6 -2pi will give you the same answer
ygarcia
Best Response
You've already chosen the best response.
0
idk where 23/pi falls
Lethal
Best Response
You've already chosen the best response.
1
Subtract 2pi from it
Lethal
Best Response
You've already chosen the best response.
1
The reason you don't know where it falls is becomes you have to do more than one revolution around the circle
ygarcia
Best Response
You've already chosen the best response.
0
so i subtract 2pi fom 6?
nelsonjedi
Best Response
You've already chosen the best response.
0
2pi = 12pi/6..So 23pi/6-12pi/6 = 11pi/6
Lethal
Best Response
You've already chosen the best response.
1
Okay good.
nelsonjedi
Best Response
You've already chosen the best response.
0
Are you familiar with the unit circle in trigonometry?
Lethal
Best Response
You've already chosen the best response.
1
Now if radians are bothering you we can convert it to degrees.
ygarcia
Best Response
You've already chosen the best response.
0
do i need like a specific calculator for this?
ygarcia
Best Response
You've already chosen the best response.
0
yes Please
Lethal
Best Response
You've already chosen the best response.
1
You could plug this into your calculator, but if this comes up on a test and you can't use one, you will be screwed.
Lethal
Best Response
You've already chosen the best response.
1
11pi/6*180/pi
ygarcia
Best Response
You've already chosen the best response.
0
Can you explain how to do it manually?
Lethal
Best Response
You've already chosen the best response.
1
That gives us 330 degrees
Lethal
Best Response
You've already chosen the best response.
1
Do you know where that is on the unit circle?
Lethal
Best Response
You've already chosen the best response.
1
hint: It's in quadrant IV
ygarcia
Best Response
You've already chosen the best response.
0
yes
Lethal
Best Response
You've already chosen the best response.
1
Okay. tell me the coordinates for it.
ygarcia
Best Response
You've already chosen the best response.
0
sqrt 2/2, -sqrt 2/2
Lethal
Best Response
You've already chosen the best response.
1
Not quite.
Lethal
Best Response
You've already chosen the best response.
1
That would be 315 degrees.
ygarcia
Best Response
You've already chosen the best response.
0
ummm sqrt 3/2 , -1/2
Lethal
Best Response
You've already chosen the best response.
1
yes. sqrt(3)/2, -1/2
Lethal
Best Response
You've already chosen the best response.
1
Okay. You should know that Cosx= x
Lethal
Best Response
You've already chosen the best response.
1
So what is the value for Cos330?
ygarcia
Best Response
You've already chosen the best response.
0
I got -.991...
Lethal
Best Response
You've already chosen the best response.
1
Keep this exact. You just gave me the coordinates. and I just told you CosƟ=x
Lethal
Best Response
You've already chosen the best response.
1
so what is the exact answer?
Lethal
Best Response
You've already chosen the best response.
1
hint: (x,y)
Lethal
Best Response
You've already chosen the best response.
1
Use the coordinates you gave me.
ygarcia
Best Response
You've already chosen the best response.
0
sqrt 3/2 , -1/2
Lethal
Best Response
You've already chosen the best response.
1
Yes and I told you cosƟ=x so what is cos330?
ygarcia
Best Response
You've already chosen the best response.
0
I don't get it /.\ I'm sorry
ygarcia
Best Response
You've already chosen the best response.
0
when I plug in Cos330 it gives me the decimal I gave you
Lethal
Best Response
You've already chosen the best response.
1
|dw:1389757103607:dw|
Lethal
Best Response
You've already chosen the best response.
1
Okay also cosƟ=A/H
This is the unit circle and the hypotenuse will always be one so basically cosƟ=H
what is Cos330?
Lethal
Best Response
You've already chosen the best response.
1
ygarcia what calculator are you using btw?
ygarcia
Best Response
You've already chosen the best response.
0
I don't have a calculator
Lethal
Best Response
You've already chosen the best response.
1
Okay. Well just finish it. Cos330=A. What is A in that triangle? A for adjacent to theta.
ygarcia
Best Response
You've already chosen the best response.
0
-1/2?
Lethal
Best Response
You've already chosen the best response.
1
|dw:1389757356882:dw|
Lethal
Best Response
You've already chosen the best response.
1
No. Adjacent means next to. So what is next to theta that isn't the hypotenuse. -1/2 is opposite.
ygarcia
Best Response
You've already chosen the best response.
0
sqrt 3/2
Lethal
Best Response
You've already chosen the best response.
1
There you go.
ygarcia
Best Response
You've already chosen the best response.
0
so the solution is sqrt 3/2?
Lethal
Best Response
You've already chosen the best response.
1
cos330=Sqrt(3)/2
Lethal
Best Response
You've already chosen the best response.
1
Yes
Lethal
Best Response
You've already chosen the best response.
1
Now let's see if you learned anything.
Tell me the sin330 if you know that sinƟ=y
ygarcia
Best Response
You've already chosen the best response.
0
-1/2
Lethal
Best Response
You've already chosen the best response.
1
Very good.
Just use the coordinates you gave me for that degree value. (sqrt(3)/2, -1/2) (x,y)
SinƟ=y and the y value for 330 is -1/2 so that's the answer.
ygarcia
Best Response
You've already chosen the best response.
0
So Cos= x value
and Sin= y value?
ygarcia
Best Response
You've already chosen the best response.
0
In reference to the circle
Lethal
Best Response
You've already chosen the best response.
1
Yeah. Because in the unit circle the radius is one, that's why it's called a unit circle, one unit.
Anytime you have something over 1 It's just whatever the numerator is.
ygarcia
Best Response
You've already chosen the best response.
0
Okay, Thanks SO MUCH!!!! I don't fully get it yet but what you explained to me helped A LOT :)
Lethal
Best Response
You've already chosen the best response.
1
You're welcome.