whe do u use radians instead of degrees?

Watch
FoOtYdUdE
Badges: 9
Rep:
?
#1
Report Thread starter 11 years ago
#1
Help please!
0
reply
jayshah31
Badges: 14
Rep:
?
#2
Report 11 years ago
#2
Either:

1) When they ask you to
2) Once start a qualification after A-levels

You may also find them useful when attempting to find the arc length of a sector, as such formulae only work in radians.
0
reply
didgeridoo12uk
Badges: 16
Rep:
?
#3
Report 11 years ago
#3
you need to use radians for differentiation and integration... so generally then
0
reply
around
Badges: 13
Rep:
?
#4
Report 11 years ago
#4
Real men use radians.
1
reply
SimonM
Badges: 18
Rep:
?
#5
Report 11 years ago
#5
It allows us to make 'small angle approximations' well, that is chords have similar lengths to arcs for segments with a small angle. This enables us to differentiate the way we expect things to happen.
0
reply
RightSaidJames
Badges: 16
Rep:
?
#6
Report 11 years ago
#6
Degrees are an invention to make pre-A-Level Maths more simple to understand. They're not useful for more complicated formulas, such as integration/differentiation, because they're not as accurate and are harder to manipulate mathematically.
0
reply
Manitude
Badges: 20
Rep:
?
#7
Report 11 years ago
#7
Calculus and certain geometry problems (both of which have been mentioned previously)
0
reply
lifeadd1ct
Badges: 0
Rep:
?
#8
Report 11 years ago
#8
(Original post by RightSaidJames)
Degrees are an invention to make pre-A-Level Maths more simple to understand. They're not useful for more complicated formulas, such as integration/differentiation, because they're not as accurate and are harder to manipulate mathematically.
They are not as accurate? Degrees are absolutely accurate however the the same cannot be said for radians because when you want to convert to radians from degrees you will have to round the figure up. So if you are unsure please do not post because other people might suffer from your knowledge or should i say, lack of knowledge
0
reply
username345307
Badges: 14
Rep:
?
#9
Report 11 years ago
#9
If you mean during exams, at AS use radians when finding the length and area of a sector, and when they tell you to e.g. cos theta = 1/2, what's theta etc.
0
reply
Dez
Badges: 20
Rep:
?
#10
Report 11 years ago
#10
Radians make much more sense than degrees, as all they essentially boil down to is fractions of a circle (well, a semicircle). Once you've used them for a while you'll wonder why on earth anyone bothered coming up with degrees. Just don't try and navigate a ship in radians.
0
reply
Dez
Badges: 20
Rep:
?
#11
Report 11 years ago
#11
(Original post by lifeadd1ct)
They are not as accurate? Degrees are absolutely accurate however the the same cannot be said for radians because when you want to convert to radians from degrees you will have to round the figure up. So if you are unsure please do not post because other people might suffer from your knowledge or should i say, lack of knowledge
Radians are usually exact (for example \sin \frac{\pi}{2} = 0) when dealing with calculus and advanced trigonometry, whereas degrees will often leave you with irrational numbers.
0
reply
WhuTom
Badges: 10
Rep:
?
#12
Report 11 years ago
#12
If you're just talking about in set A-level maths questions regarding trigonometry, (C3 trigonometry for example) then I always switch from degrees to radians as soon as I see the pi symbol. It just means 180 degrees anyway, but if the expression or range is in terms of pi you always do the problem in radians. Don't take this for all types of maths though, I just tried to explain best I could
For a more detailed, accurate answer (i.e. in maths in general) I'm sure someone else here can explain it through
0
reply
py0alb
Badges: 3
Rep:
?
#13
Report 11 years ago
#13
because then you get the right answer, rather than the wrong answer.
0
reply
generalebriety
Badges: 16
Rep:
?
#14
Report 11 years ago
#14
Always use radians, as soon as you know they exist. Degrees are silly, and serve to do nothing other than protect GCSE students from nasty numbers.

(Original post by lifeadd1ct)
Degrees are absolutely accurate however the the same cannot be said for radians because when you want to convert to radians from degrees you will have to round the figure up.
Degrees are absolutely accurate. So are radians. Why would anyone ever want to convert between the two? What a ridiculous idea.
0
reply
SimonM
Badges: 18
Rep:
?
#15
Report 11 years ago
#15
(Original post by Dez)
Radians are usually exact (for example \sin \frac{\pi}{2} = 0) when dealing with calculus and advanced trigonometry, whereas degrees will often leave you with irrational numbers.
Seriously. Listen to the guy.

\cos 90^{\circ} isn't approximately 0, it is exactly 0.

Besides which, do you know under what conditions \cos \frac{p}{q} \pi is rational?
0
reply
SirMasterKey
Badges: 18
Rep:
?
#16
Report 11 years ago
#16
If in an exam paper just look for the super script. An o means degrees, an r means radians.

Most other stuff regarding radians as already been said.
0
reply
nuodai
Badges: 17
#17
Report 11 years ago
#17
(Original post by Dez)
Radians are usually exact (for example \sin \frac{\pi}{2} = 0) when dealing with calculus and advanced trigonometry, whereas degrees will often leave you with irrational numbers.
Is \sin \frac{\pi}{2} really zero? :p:

But as others have said OP, use radians unless otherwise specified, and leave your answers in terms of \pi or surds unless otherwise specified, then you won't go far wrong.

I've not used degrees since starting uni.
0
reply
tiny hobbit
Badges: 15
Rep:
?
#18
Report 11 years ago
#18
When differentiating or integrating trig functions.

Or when the question starts talking about pi.
0
reply
ukdragon37
Badges: 14
Rep:
?
#19
Report 11 years ago
#19
Always.

Try to use radians as often as possible unless you have to or it's much easier to use degrees (rare). Radians are far more useful and that's the best way to get used to them.
0
reply
phen
Badges: 14
Rep:
?
#20
Report 11 years ago
#20
(Original post by didgeridoo12uk)
you need to use radians for differentiation and integration... so generally then
I'm not sure I know what you mean. o__o

(Original post by lifeadd1ct)
They are not as accurate? Degrees are absolutely accurate however the the same cannot be said for radians because when you want to convert to radians from degrees you will have to round the figure up. So if you are unsure please do not post because other people might suffer from your knowledge or should i say, lack of knowledge
You might as well say degrees aren't accurate by the same (silly) reasoning.
0
reply
X

Quick Reply

Attached files
Write a reply...
Reply
new posts
Back
to top
Latest
My Feed

See more of what you like on
The Student Room

You can personalise what you see on TSR. Tell us a little about yourself to get started.

Personalise

Who is winning Euro 2020

France (125)
27.53%
England (163)
35.9%
Belgium (33)
7.27%
Germany (43)
9.47%
Spain (10)
2.2%
Italy (39)
8.59%
Netherlands (14)
3.08%
Other (Tell us who) (27)
5.95%

Watched Threads

View All