While we seem to be OT... [Archive]

NovceGuru

01-17-2006, 02:25 PM

lets help NovceGuru with his girlfriends trig! Its been about 4 years since I've done this stuff, its fairly simple, I just dont remember the process.

http://jsreedinc.com/damnmath.jpg

I'm pretty sure for the first one its tan 36 = a/48

and for the second one I think its cos 36 = c/48

After that i'm not sure what you do to find the variables...

Pretty basic stuff....just been a while :)

Thanks

angrypancake

01-17-2006, 02:28 PM

uhhhhhhhhhhhhhhhhhhhhhhhhhh

Cactuar

01-17-2006, 02:33 PM

uhhhhhhhhhhhhhhhhhhhhhhhhhh

x2

Anthony (M5 in Calgary)

01-17-2006, 02:34 PM

uhhhhhhhhhhhhhhhhhhhhhhhhhh

OK brain, you don't like me and I don't like you. Let's just get through this and I can get back to killing you with beer.

It's a deal!

632 Regal

01-17-2006, 02:44 PM

angrypancake

01-17-2006, 02:47 PM

ryan roopnarine

01-17-2006, 02:56 PM

i don't think there's a way to do this problem without the cosine rule, and the cosine rule needs two sides and an angle, because the trig functions are ratios. for example

a/sin = b/sin = c/sin

if you have any 3 parts of this, you can solve for the rest.

i thought about doing this by vectors, but you need more info to do this.

are you CERTAIN these problems don't involve right triangles?

i can see how you could do this if you put it onto graph paper, and assign units, and use a protractor. what is the name of this class? trig? there are other ways to do this if i know where its coming from.

NovceGuru

01-17-2006, 03:00 PM

They're not, or it would of specified it...unless they screwed up, what would the answer be if it was? any of the multiple choice answers? (on the first one, 2nd one got cut off)

NovceGuru

01-17-2006, 03:21 PM

I'm pretty sure theres a way to just solve this using a calculator, on several other problems i'm getting tan 55 = x/40 ....this is why I didn't become a math teacher :P

ryan roopnarine

01-17-2006, 03:21 PM

on the back of a piece of scrap paper i have here (so im sure they're wrong)

i have:

<a=36
<b=100.7
<c=43.3

A=45
B=48
C=66

found the angles using tan first from <a. then flipped the paper upside down because i figured that segment AC was the hypotenuse. used the pythagorean theorem on A=45 B=X and C=hyp=66.

48^2 + X = 66^2
2304 +X =4356
x^2=2052
x=45.29

****, i typed in the wrong one, that wasn't the piece of paper with the right answer on it

sorry, im trying to do two things at once. i guess you'll have to wait for somebody with a brain to do it.

NovceGuru

01-17-2006, 03:24 PM

haha well thanks for spending some time on it :)

dacoyote

01-17-2006, 03:49 PM

NovceGuru

01-17-2006, 03:56 PM

One angle and the hypotenuse is given
opp = sin (angle) x hyp
adj = cos (angle) x hyp

One angle and the opposite side is given
hyp = opp/sin (angle).
adj = opp / tan (angle)

One angle and the adjacent side is given
hyp = adj / cos (angle)
opp = adj x tan (angle)

I could give you an answer if you will confirm what sides are what...
It's been to long since I last had to do this sorta stuff...

Thanks for the input...i'm not sure what you mean by confirming, the only information I have is what is in the picture....glad to see somebody else from ohio, do you know of any BMW clubs/meets in this state?

632 Regal

01-17-2006, 03:59 PM

okay, its either 6 or 9 for sure.

DaCan23

01-17-2006, 04:03 PM

The shortest distance between 2 points is a straight line

dacoyote

01-17-2006, 04:07 PM

Thanks for the input...i'm not sure what you mean by confirming, the only information I have is what is in the picture....glad to see somebody else from ohio, do you know of any BMW clubs/meets in this state?

It's been to long to be sure what side they are looking for for sure off the picture....

I gotto the meets in Chi-land.... but thats about it....

What part of Ohio are you in... I am arround Ohio a lot...

DaCan23

01-17-2006, 04:07 PM

If Mary is twice as old as her sister Tina and Tina is 5 years younger than her sister Lisa and Lisa is 2 years older than her sister Alison and Alison is 15 years old..... How many years until Tina is "legal" ?

dacoyote

01-17-2006, 04:07 PM

The shortest distance between 2 points is a straight line

That is not always true.....

DaCan23

01-17-2006, 04:12 PM

Well considering after a few drinks your straight line looks like a W and you thought you drove straight home

That is not always true.....

NovceGuru

01-17-2006, 04:16 PM

It's been to long to be sure what side they are looking for for sure off the picture....

I gotto the meets in Chi-land.... but thats about it....

What part of Ohio are you in... I am arround Ohio a lot...

Yeah its been to long for me to! :P I am about 20 miles south of mansfield in Knox county, about 10 miles north of Mt. Vernon, if you know where that is.

dacoyote

01-17-2006, 04:21 PM

dacoyote

01-17-2006, 04:21 PM

Well considering after a few drinks your straight line looks like a W and you thought you drove straight home

and that the chick you found is hot.....

dacoyote

01-17-2006, 04:25 PM

Yeah its been to long for me to! :P I am about 20 miles south of mansfield in Knox county, about 10 miles north of Mt. Vernon, if you know where that is.

Butler? or just about there.... I drive by there on a weekly basis going to see the gf... flying down 71

DaCan23

01-17-2006, 04:36 PM

Woo hoo you get a gold star.... I cant believe someone actually did the math lol... I did calc it out 1st...

Tina will be 18 in 6 years...

DanDombrowski

01-17-2006, 04:39 PM

Thinking

dacoyote

01-17-2006, 04:52 PM

Woo hoo you get a gold star.... I cant believe someone actually did the math lol... I did calc it out 1st...

Simple stuff like that I can do while I running the help desk...

dacoyote

01-17-2006, 04:52 PM

Thinking

Processing... Processing

-Data

DanDombrowski

01-17-2006, 04:57 PM

It has to be a right triangle to solve it. Think about it this way:

Draw a horizontal line, call it B, and make it 48 long. The left side of the line is angle c, the right side is angle a. Angle a is 36 degrees, so side C (opposite of angle c on the left of side B) starts going Northwest. C can be any length and still satisfy that B is 48 and a is 36 degrees. So A can be any length. Therefore, it has to be a right triangle in order to know the answer.

Comprende?

rob101

01-17-2006, 04:58 PM

I don't remember that kind of trig, or at least i don't understand wtf this M>A = angle business is. sure i can do trig but i've never seen that before. Think i'll just go back to being an engineer.... much easier than that problem.

DanDombrowski

01-17-2006, 05:01 PM

It means the measure of angle a is 36 degrees.

NovceGuru

01-17-2006, 05:44 PM

Butler? or just about there.... I drive by there on a weekly basis going to see the gf... flying down 71

Man, butler is about 6 miles from my house lol. Maybe one of these days when my car is actually clean we can meet up and trade rides for a while :P Is she more south or north of butler?

dacoyote

01-17-2006, 06:09 PM

Man, butler is about 6 miles from my house lol. Maybe one of these days when my car is actually clean we can meet up and trade rides for a while :P Is she more south or north of butler?

She is about 5 miles out Bellefontaine OH .... it's about 45 minutes north west of Columbus

Incantation

01-17-2006, 06:14 PM

when in doubt, pick c

Phil Sanderson

01-17-2006, 08:05 PM

...SOHCAHTOA Sin=Opposite/Hypotenuse, Cos= Adjacent/Hypotenuse and Tan=Opposite/Adjacent. To remember SohCahToa pronounce it like Krakatoa, the volcano which erupted in 1883, killing thousands, the biggest volcanic eruption in recorded history.

So, to get side a
Tan 36 = a/48
Tan 36 x 48 = a
a = 34.87

to get side c
Sin 36 = 34.87/c
Sin 36 x c = 34.87
c = 34.87/Sin 36
c = 59.33
Of course as Trig is only used on right anlge triangles, you will find that Angle B is 54degrees.

So
Angle A = 36degrees (given)
Angle B = 54degrees
Angle c = 90degrees

Side a = 34.87
Side b = 48 (given)
Side c = 59.33

regards
Phil

NovceGuru

01-17-2006, 10:51 PM

:D :D :D Thank you!! I knew a brain would come along and figure it out :) I have SOHCAHTOA scribbled all over my papers, I just wasn't sure how to apply it, thanks a lot, very much appreciated.

NovceGuru

ryan roopnarine

01-17-2006, 11:02 PM

im glad that somebody came along and said that this HAD to be a right angle problem, i was feeling retarded for a while. was going to draw it on graph paper, using the cubes as units of 1 (to scale) , estimate where it ended up and worked backward from there. this problem makes no mathematical sense (with respect to trig) if they aren't right angles.

McWatters

01-18-2006, 12:29 AM

This is like last weeks math lesson all over again, I ****ing hate numbers.

Cheers

J.McWatters

Kalevera

01-18-2006, 12:41 AM

Is your girlfriend like....14? I had no idea that was legal down there :D We get arrested for stuff like that in NE Ohio

best, whit

forrer13

01-18-2006, 10:45 AM

I think the answer is M5, but isn't that always the answer???

NovceGuru

01-18-2006, 03:56 PM

Well im glad somebody figured it out! Nah shes 17, 18 in April 4th...maybe she'll get me an M5 for her birthday.........wait...Now onto the law of sines....SOB!

liquidtiger720

01-18-2006, 05:02 PM

hold on hold on...my turn. now that your problem is solved. its time to help liquidtiger720 with his hmwrk! I'm taking a picture now. will be up in a moment.

Edit: Here we go. I'm stuck...I need your guys's help please.

http://img.photobucket.com/albums/v457/liquidtiger720/IMG_mathLarge.jpg

NovceGuru

01-18-2006, 07:41 PM

Damn....

DanDombrowski

01-18-2006, 10:22 PM

Integrate y from x=0 to x=b/2, then revolve that around the y axis. I don't remember how to find the volume of a figure of revolution, but I'd be willing to start with integrating your resulting area over 2* pi

Then compare that to the volume of the y = h revolved around 2*pi. Simplify.

DanDombrowski

01-19-2006, 09:05 AM

Alright, I looked at this at this last night, and then I tried to solve it at work today, but photobucket is blocked at work, so I don't know if I'm starting with the right equation.

You have to take the integral of x^2 * pi*dy (since you're revolving around y axis) over the range 0 to h. In order to do that, you're going to have to re-arrange the equation to get it in terms of x = ....I can't get the volume of the parabaloid to be 3/2 * the volume of the cone, but I think my starting equation is wrong. Could you host the picture on bimmer.info or let me know what the equation for the parabaloid is?

Oh, one more thing. You need to come up with an equation for the line that defines the outside of the cone. Its y = 2*h/b *x.